Free technical library
A large selection of riddles on various topics for adults and children.
 Comments on the article
Mathematical riddles
Click on the link below for the answer.
Riddles in Russian | Riddles in Ukrainian
Mathematical riddles in Russian
(8 + 12 - 20) = (10 + 15 - 25)
We take the common factor out of brackets:
4 (2 + 3 - 5) = 5 (2 + 3 - 5)
We reduce (2 + 3 - 5) on each side and get:
4 = 5.
Where is the mistake?
(Equality is achieved by multiplying by zero (2 + 3-5) \u0d XNUMX, and you cannot divide by zero)
1. How to write the number 100 with six digits 4?
2. How to write the number 100 in seven digits 4?
3. How to write the number 1000 in fifteen digits 4?
(1: 4+4*4-44+4
2: 44+4*4/44+4
3: 44/4+4/4*44-44+4/44+444)
45% of the lottery's earnings are spent on paying out winnings.
How many tickets worth 5 francs should the organizers of the lottery distribute if 87 francs are supposed to be spent on paying out the winnings?
(Let x be the number of lottery tickets to be distributed. Then
5x \u87d 300 * 100 / 45 \u194d 000,
x = 38.
This means that in order to spend the target amount of 87 francs on the payment of winnings, the organizers of the lottery need to sell 300 tickets worth 38 francs each)
Brother Sebastian and brother Tadeusz are bell ringers, their duties include beating time with bells on the town hall tower. On reflection, I realized that their job is not easy. For example, you need to hit five hours in exactly 25 seconds. Based on this, determine how long it will take to strike ten o'clock?
(The brothers will need exactly 56 and 1/4 seconds to strike ten hours. Here's how we counted it: between the first and fifth strikes of the bell, there are four intervals. Divide the total time of 25 seconds by four and get six and a quarter seconds per interval There are nine intervals between the first and tenth strokes of the bell.We multiply six and a quarter by nine and get 56 and 1/4 seconds - the desired answer)
There were some sparrows and some columns. As two sparrows sit on one column, there will be one extra column, and as one sits one at a time, there will be an extra sparrow. How many columns and sparrows were there?
(Three columns and four sparrows)
In America, the date July 1, 2003 is written as follows: 7/1/2003, and in other countries: 1/7/2003. If you do not know what format the number is written in, then how many dates in a year can be misinterpreted?
(If there is a number 13, you can guess that this is a day, not a month. That is, you can get confused in numbers up to 12, including 12. There are 12x12 = 144 total possible combinations. But each month will have one date, which in each case will be understandable correct, for example 7/7/2003. As a result, everything can be interpreted incorrectly days 144-12 = 132)
The pet store sells large and small birds. A large bird is twice as expensive as a small one. The lady who went to the store bought 5 big birds and 3 small ones. If she had bought 3 large birds and 5 small ones instead, she would have spent $20 less. How much does each bird cost?
(The price of a large bird is $20 and a small bird is $10. Solution: let the price of a small bird be x, then the big bird will be y=2x. The lady bought 5 large and three small ones, that is 5y + 3x. If she bought 3 large five small ones, i.e. 3y + 5x, would have spent $20 less. 5 -> y=3x=3)
In the month, three Sundays fell on double numbers. What day of the week was the seventh of this month?
(Friday. Sundays will fall on the numbers: 2, 9, 16, 23, 30)
Given money - 1 hryvnia.
With this money you need to buy exactly 100 eggs - goose, duck, chicken:
- goose - 5 kopecks / piece;
- duck - 3 kopecks / piece;
- chicken - 1 kopeck / ten.
You need to buy 100 eggs and exactly for the hryvnia - without a trace.
(Goose - 16, duck - 4, chicken - 80)
Two freight trains, both 250 m long, travel towards each other at the same speed of 45 km/h. How many seconds will pass after the drivers have met before the conductors of the last cars meet?
((There are no conductors on freight trains. But hypothetically :) At the time of the meeting of the drivers, the distance between the conductors will be 500 m, because each train travels at a speed of 45 + 45 = 90 km / h, or 25 m / s, the required time is 500 :25=20s)
Ten dogs and cats were fed 56 biscuits. Each dog got 6 biscuits, each cat - five. How many dogs and how many cats? Try to solve the task without using either a system of equations or a search of options.
(If there were only dogs, then 60 biscuits would have been eaten. But since 4 fewer biscuits were eaten, therefore, there were 4 cats (one missing biscuit up to 60), so there were 10 - 4 = 6 dogs)
To weigh the goods, the seller uses a pan balance and four weights with a total weight of 40 kg. Moreover, using different combinations of weights, you can weigh any load, the mass of which is expressed as an integer number of kilograms (from 1 to 40 kg).
How much does each weight weigh?
(Kettlebells weighing 27, 9, 3 and 1 kg)
Dr. Aibolit distributed 2006 miraculous pills to four sick animals. The rhino got one more than the crocodile, the hippo got one more than the rhinoceros, and the elephant got one more than the hippo. How many pills will the elephant have to eat?
(503 tablets)
An ancient task on a domestic topic. It was asked to his students by the arithmetic teacher Jacob from Coburg, whose textbook was printed in 1599 in Frankfurt.
The distance between the 2 cities is 260 miles. Two messengers come out from both cities towards each other. One of them daily walk 2 miles more than the other. After 2 days, the messengers meet.
How many miles does each messenger travel daily?
(Let y be the number of miles traveled in one day, and x the other messenger. Then
y = x + 2, (1)
12x + 12y = 260. (2)
Substituting (1) into (2), we obtain
12x +12(x+2) = 260,
whence
x = 9 and 5/6.
Thus, one messenger traveled 9 and 5/6 miles per day, and the other 11 and 5/6 miles)
If one and a half hens lay one and a half eggs in a day and a half, how many will two hens lay in two days?
(8/3 eggs. The basis of the task lies in the difficulty of perceiving such "things" as - the gender of the chicken, the gender of the egg, and so on)
If a person goes to work on foot, and goes back by transport, then in general he spends an hour and a half on the road. If he travels in both directions by transport, then the whole journey takes him 30 minutes. How many times does a person need to travel if he goes to work and back on foot?
(Using transport, a person spends 30 minutes on the way back and forth. Therefore, the one-way journey takes 15 minutes. It turns out that on foot he can get to work in 1 hour and 30 minutes - 15 minutes \u1d 15 hour and 2 minutes. The whole journey will take twice as long - 30 hours and XNUMX minutes)
There is a cube - black on the outside, but white on the inside. Its height is equal to its width and thickness, and is three cubits.
Tasks:
1. How many cuts will it take to divide a large cube into small cubes only one cubit in size?
2. How many cubes will be obtained after such cutting?
3. How many of the dice will have 4 black sides, how many will have 3, 2, and only one black side?
4. How many small black faces will there be, and how many cubes will be completely white on all sides?
(1. Only six cuts are needed. Each of the faces of the cube must be cut twice.
2. You will get 27 small cubes: three layers and each - nine cubes laid out in a 3 x 3 square.
3. No cubes with four black sides. With three black faces will be those cubes that are cut from the tops of a large cube. A cube has only eight vertices. In order for the small cube to have only two black faces, it must be cut from the middle of the edge of the large cube. This means that there will be twelve small cubes with two black faces. Well, with one black face you get 6 cubes.
4. From each large face, 3 x 3 = 9 small ones are obtained. And since there were six large faces, then small ones will come out 3 x 3 x 6 = 54. A cube with all sides white will get only one - from the very middle of a large cube)
The remarkable Hungarian pop calculator Ferenc Pataki, who is able to mentally multiply 2 three-digit numbers in a matter of seconds, speaking on television in 1979, demonstrated the following trick.
"Multiply your shoe size by 2, add 39 to the product, multiply the resulting amount by 50, add 29 to the product, subtract the year of your birth from the sum," Pataki asked. To the surprise of the audience, each of them received a four-digit number, the first two digits of which meant the shoe number, and the last two - the viewer's age at the end of the calendar year.
Explain the basis of Ferenc Pataky's trick.
(For any natural numbers a and b from the admissible sets (shoe size and age), the following identity holds:
[(2a+39) * 50+29] - (1979-b) = 100a+b)
From 36 pieces of metal, the turner was instructed to turn 36 amphorae on a lathe. It is known that if you collect shavings from 6 carved amphorae and melt them down, you can carve another amphora out of it. How many unaccounted for amphorae can a turner keep?
(You will get 7 additional amphoras: 6 from the remains of the first 36 and one more from the new six)
From the numbers 5, 5, 5, 1 and simple arithmetic operations "+", "-" "*", "/" you need to get the number 24.
((5-1/5)*5=24)
How do you write down the number 3 three times to get 4 in the end?
(3:3+3)
How to measure 15 minutes, having a seven- and eleven-minute hourglass at hand?
(We set the clock at 7 and 11 minutes at the same time. As soon as the clock is completely oversleeped for 7 minutes, we turn it over. The clock for 11 is oversleeped for another 4 minutes, as soon as it is overslept, we turn over the clock again for 7 minutes (in which only 4 minutes have run), therefore, they will measure 4 more minutes, which together with 11 makes 15 minutes)
What three numbers, when added or multiplied, give the same result?
(1, 2, 3)
When my father was 31, I was 8 years old, and now my father is twice my age. How old am I now?
(23)
A flock of geese flew, the uncle saw them and said:
- Apparently, there are a hundred of you!
And the geese answer:
"If there were so many of us,
Yes, there would be so much
And half as much
And a quarter as much
And you would be with us - then there would be a hundred."
How many geese?
(36 гусей: 36+36+18+9+1=100)
The minute hand of a clock is 2 cm long, and the hour hand is 1,5 cm long. Find the ratio of the speeds with which the ends of the hands move.
(Let v1 be the linear speed of the end of the minute hand and v2 be the hour hand. Then
v1 = s1/t1 = 2pr1/t1 = 2p. 2/1 \u4d XNUMXp cm / hour,
v2 = s2/t2 = 2pr2/t2 = 2p. 1,5/12 \u4d p / XNUMX cm / hour,
v1:v2 = 4p:p/4 = 16:1.
This means that the end of the minute hand moves 16 times faster than the end of the hour hand)
On Klaus's watch, the minute divisions are marked with small strokes. Glancing at his watch at six o'clock in the afternoon, Klaus found that the large hand was 3 divisions behind the small one.
How much was on the clock?
(At 5.00:25, the minute hand is separated from the hour hand by 3 minute divisions. At the moment when Klaus looked at his watch, the long hand was only 22 divisions behind the small one and, therefore, managed to pass 1 divisions. In 1 minute, the long hand passes 1 division, and small 12/1 divisions Therefore, in 1 minute the minute hand catches up with the hour hand by 1 - 12/11 = 12/22 divisions, and in order to go through 22 divisions, the minute hand will need 11: (12/24) = XNUMX min.
Therefore, Klaus looked at his watch at 5.24:XNUMX)
We are both 63 years old together. I am now twice as old as you were when I was as old as you are now.
How old am I and how old are you?
(Currently I am 36 and you are 27. And once I was 27 and you were 18)
Write in digits the number consisting of 11 thousand, 11 hundreds and 11 units.
(11000 + 1100 + 11 = 12)
Write 100 with five ones and then five fives.
((111-11), (5+5+5+5)*5 или (5*5*5-5*5))
They found a dime and divided it: for men, one and a half kopecks, for women, a kopeck, and for children, a quarter of a kopeck. How many men, women and children were there?
(One man, five women, fourteen children)
One biologist discovered an amazing variety of amoebas. Each of them in a minute is divided into two. A biologist puts one amoeba in a test tube, and an hour later the whole test tube is filled with amoeba. How long would it take for the whole test tube to be filled with amoebas if not one amoeba but two were first put into it?
(59 minutes)
One brick weighs 1 kilogram and another half a brick. How much does one brick weigh?
(2 kg)
Once, we involuntarily witnessed the following conversation.
- Did I understand you correctly? You claim that you have been a member of the chess club twice as long as I have.
- Completely correct.
- But as far as I remember, you used to say that you were a member of the chess club three times longer than me?
- Two years ago? But then my experience as a member of the club really was 3 times more than yours, and now only 2 times.
How many years have each of the two interlocutors been members of the chess club?
(The conditions of the problem allow us to write the equations
(x - the experience of one interlocutor, y - the other):
y=2*x
y - 2 * 3(x - 2),
whence x = 4, y = 8.
This means that one employee has been in the chess club for 8 years, the other for 4 years)
One woman went to the garden to pick apples. To leave the garden, she had to go through four doors, each with a guard. The woman gave half of the apples she had plucked to the guard at the first door. Having reached the second guard, the woman gave him half of the apples that were left. She did the same with the third guard; and when she shared the apples with the guard at the fourth door (with whom she did as with the previous ones), she had only 10 apples left. How many apples did she pick in the garden?
(If x is the number of apples the woman picked in the garden, then the first guard got x/2 apples, the second got x/4 apples, the third got x/8 apples, and the fourth got x/16 apples. Since x/16 = 10, then x \u160d 160. Therefore, the woman collected XNUMX apples in the garden)
Here is the expression 987654321=100. Make it correct by using 4 "+" or "-" signs on its left side.
(98 - 76 + 54 + 3 + 21 = 100)
The sawyers cut the deck into meter-long pieces. The length of the deck is 5 meters. Cutting the deck across takes 1,5 minutes each time.
How long did it take to cut the entire deck?
(Since 5 cuts are needed to divide a 4 meter deck into meter segments, a total of 6 minutes is needed)
Having traveled a third of the way, the passenger of the fast train finally fell asleep. When he woke up, he had half the distance to his destination station that separated him from his destination when he fell asleep.
What part of the journey did the train cover while the passenger was sleeping?
(Since (1/2) * (2/3) = 1/3, the passenger slept 1/3 of the way)
Five diggers dig a 5 m ditch in 5 hours. How many diggers will dig 100 meters of ditch in 100 hours?
(5 diggers)
The fish is wonderfully prepared here,
Boiled trout is the king of all dishes.
Order is accepted. All is ready. Bear!
A serving of fish is served on the table.
But what is that noise? The cooks scream
"For a portion, we do not have enough table,
And we could not serve two on the table.
Someone's table would be completely without fish."
You could not name
Us number of servings of trout
And the number of tables
Where cooks are praised?
(Let x be the number of servings of fish prepared by skilled chefs, y the number of tables. Then
y + 1 = x,
2(y-1)=x,
whence y +1 = 2(y-1), y = 3, x = 4.
So, the chefs prepared 4 servings of fish, and there were 3 tables for the guests)
The seven old women went to Rome. Each old woman has seven donkeys, each donkey carries seven sacks, each sack contains seven loaves, each loaf contains seven knives, each knife in seven sheaths. How many items in total?
(7^6)
The fabulous gnome needs a new candle every night, with which he shines for himself on the road, walking around the city. He can make 1 new candle out of 5 candle stubs. If he has 25 candle ends, how many nights will he have enough new candles to last?
(For 6 nights. He can make 5 new candles from 25 cinders, and when they burn out, he can make the sixth of the 5 cinders that remain of them)
A rock climber stands on top of a smooth, steep rock 100 meters high. At a height of 50 meters there is a ledge where you can make an intermediate stop. The climber has a rope 75 meters long. How will he get off the cliff?
(It is necessary to do this: we cut the rope into 2 pieces of 25 and 50 m, then we fasten piece 25 to the top and make a loop at the end, then we put one end of a piece of 50 m and tie it to the second end, in total we will get 50 m, what exactly you need to reach the ledge, and going down to the ledge we pull up the place of the bundle of 50 m of the piece, untie it, fasten to the ledge and go down)
How much is two plus two divided by two?
(3. The first action is division, there was no talk about brackets)
How many edges does a hexagonal pencil have?
(8 faces)
How many times during the day do the minute and hour hands of a clock form a right angle?
(For 1 hour, the hour hand describes an angle of 30 °, and for 1 minute - an angle of 0,5 °. The minute hand for 1 minute describes an angle of 6 °. Since 90: (6 - 0,5) \u16d 4 (11 / 16), the minute and hour hands form a right angle for the first time 4 (11 / 12) minutes after both are at 16. Since n - 4 (11/24) = 60 - 88, we get n = 0 (this number includes the angles of 90°, 180°, 270°, XNUMX° formed by the minute and hour hands).
During the day, the minute and hour hands form a right angle 44 times)
How many flowers do I have if all but two are roses, all but two are tulips, and all but two are daisies?
(3 (three flowers))
A flock of doves flew up to a tall tree. Part of the doves sat on the branches, while the other settled under the tree. The doves that were sitting on the branches say to those below: “If one of you flew up to us, then you would be three times less than all of us together, and if one of us flew up to you, then you and I would be equal." How many doves sat on the branches and how many under the tree?
(Let x be the number of pigeons that sat on the tree, and y be the number of pigeons that settled under the tree. Then
y - 1 = (x + y) / 3
and furthermore, x - 1 = y + 1, i.e. x = y + 2.
Substituting x = y + 2 into the first equation, we get
(y - 1) - 3 = y + 2 + y,
3y - 3 = 2y + 2,
y=5.
So x = y + 2 = 7.
From here, 7 doves sat on a tree, and 5 doves settled under a tree)
The clock hands have just aligned. After how many minutes will they "look" in opposite directions?
(Let x be the length of time (in minutes) that must elapse before the hands are on the same straight line and directed in opposite directions. The minute hand will have time to pass x minute divisions of the dial during this time, and the hour hand - x / 12 minute divisions. When the hands are on the same straight line and are directed in opposite directions, they will be separated by 30 minute divisions of the dial.
Therefore, at this time:
x - x/12 = 30,
whence x = 32 (8/11).
After 32 (8/11) min. after the minute and hour hands coincide, they will "look" in opposite directions)
The combined age of family members of 4 is 68, and 4 years ago was 53. How old is the youngest member of the family?
(3 years)
Cockroach Valentin announced that he can run at a speed of 50 m / min. They did not believe him, and rightly so: in fact, Valentin mixed everything up and thought that there were 60 centimeters in a meter, and 100 seconds in a minute. At what speed (in "normal" m/min) does the cockroach Valentin run?
(Cockroach Valentine runs at a speed of 18 m / min)
Three years ago, Nastya was 7 times older than her sister Veronica. Two years ago, Nastya was 4 times older than Veronica. A year ago, Nastya was 3 times older than Veronica.
How old are Nastya and Veronica?
(Nastya is 10 years old, and Veronica is 4 years old. Proof: let Nastya be x years old and Veronika y at the moment. Then, three years ago, one could write: x-3=7*(y-3), two years ago : x-2=4*(y-2), a year ago: x-1=3*(y-1) From the last equation, x=3*y-2, Substituting this into the second equation, we get: 3*y-(2-2=4*(y-2) so y=4. Substituting the value of y into the equation for x, we get: x=3*4-2=10)
The three were playing chess. A total of three games were played. How many games did each play?
(two)
I have money in two pockets; when I transfer one ruble from one, it will be equal, and when I transfer one ruble from the second to the first, then in the first it will be twice as much as in the second. How many rubles in each pocket?
(Five and seven)
Write five positive integers whose sum is 20 and whose product is 420.
(7, 5, 4, 3, 1)
The owner is sitting on the bank of a pond that is overgrown with weeds. The number of weeds is doubling every day. He's going to start clearing as soon as half the pond is overgrown. A month later, half of the pond was overgrown. How many days does he have to clean up?
(Day 1. Half of the pond is already overgrown)
The number of three different digits is subtracted from the number that consists of the same digits in reverse order. The result consists of the same three digits, arranged again in a different way. What are these numbers?
(954 - 459 = 495)
Mathematical riddles in Ukrainian
(8 + 12 - 20) = (10 + 15 - 25)
Blame for the bows of the blazing multiplier:
4 (2 + 3 - 5) = 5 (2 + 3 - 5)
Quickly (2 + 3 - 5) from the skin side and obsessed:
4 = 5.
Where is the pardon?
Vidpovid
(Rіvnіst reach for rahunok multiplied by zero (2+3-5) = 0, and dilute by zero is not possible)
1. How to write the number 100 with 4 digits XNUMX?
2. How to write the number 100 soma in digits 4?
3. How to write down the number 1000 fifteenth in digits 4?
Vidpovid
(1: 4+4*4-44+4
2: 44+4*4/44+4
3: 44/4+4/4*44-44+4/44+444)
45% of the lottery income is used to pay the winnings.
How many vouchers for the 5 francs payment will be distributed by the organizers of the lottery, so that I will be transferred 87 francs to the payment?
Vidpovid
(Let's x - the number of lottery tickets that will give you a chance to win every day. Todi
5x \u87d 300 * 100 / 45 \u194d 000,
x = 38.
Also, in order to spend the sum of 87 francs for the payment of winnings, the organizers of the lottery need to sell 300 vouchers for 38 francs each)
Brother Sebastian and brother Tadeusz are bell ringers, at their bindings they should ring the hour at the town hall. Thinking about it, I realized that working in them is not easy. For example, you need to hit five years exactly in 25 seconds. Vykhodyachi izgogo, you mean, how many will be needed for an hour, to see the tenth year?
Vidpovid
(The brothers will need exactly 56 and 1/4 seconds, so that they will hit the tenth year. From yak mi tse cheered: between the first and five blows in the dzvin - chotiri intervals. by one interval Between the first and ten strokes of the bell there are nine intervals.
Bulo skіlkis gorobtsіv і sсіlkis stoptsіv.
If you sit down two gorobtsі on one stovpets - there will be one extra stovpets, and if you sit down one at a time - there will be an extra gorobets. Skіlki bulo stovptsіv i gorobtsіv?
Vidpovid
(Three stovptsі and chotiri gorobtsі)
In America, the date of March 1, 2003 is recorded as follows: 7/1/2003, and in other countries: 1/7/2003. If you don’t know, in which format the number is written, then how many dates for the rotation can be incorrect?
Vidpovid
(Also, the number 13, you can guess the day, not the month. So you can get lost in numbers up to 12, including 12. The most possible combinations are 12x12=144. got it right , for example, 7/7/2003. With a bag of everything, it is possible to vitlumachit wrong days 144-12 = 132)
Given pennies - hryvnia.
For the price of pennies, it is necessary to buy exactly 100 eggs - goose, kachinih, chicken:
- geese - 5 kopecks / one;
- kachini - 3 kopecks / item;
- chickens - 1 kopeck / ten.
Buy at least 100 eggs and for a hryvnia exactly - without a decision.
Vidpovid
(Goose - 16, kachinih - 4, chicken - 80)
Two freight trains, offending at a distance of 250 m, travel one to one with the same speed of 45 km / year. How many seconds passed after the drivers started to sound, the conductors of the remaining cars started to sound first?
Vidpovid
((There are no conductors on freight trains. But it’s hypothetical::) At the time of the sound of the machines, the distance between the conductors will be 500 m, so the leather train will be 45 + 45 = 90 km / year, or 25 m / s, the sound of an hour will be є 500:25=20s)
Ten dogs and guts were served with 56 biscuits. The skin dog got 6 biscuits, the skin intestines - five. How many bulo dogs and how many guts? Try virishiti zavdannya not vikoristovuyuchi nі systems equal, nі enumeration of options.
Vidpovid
(Yakbi were only dogs, then 60 biscuits were taken. But oscills were taken 4 biscuits less, later, there were 4 guts (one daily biscuit up to 60), so there were 10 dogs - 4 = 6)
For zvazhuvannya goods, the seller is dressed with cup teres and chotirma weights with a 40 kg wagon. Moreover, vikoristovuyuchi different combinations of weights, you can call any kind of vantage, the mass of which is manifested by a whole number of kilograms (from 1 to 40 kg).
How important is skin weight?
Vidpovid
(Weights with a vag in 27, 9, 3 and 1 kg)
From 36 pieces of metal, turners, 36 amphoras were entrusted to turn at the Turner's bench. Apparently, if you take shavings from 6 turned amphorae and melt them down, then you can turn one amphora from it. How many unwrapped amphoras can you get yourself a tokar?
Vidpovid
(Weide 7 additional amphoras: 6 from the leftovers of the first 36 and one more from the new six)
A flying dove flew up to a tall tree. Part of the doves was strong on the needles, and the other part was growing under the tree. The pigeons that were sitting on the hind legs, talking to the quiet, downstairs: "Yakby one of you is angry before us, then you would be three times less, lower us all at once, and one of us is angry with you, then we would be out of you." equally". How many pigeons were sitting on the needles and how many pigeons were under the tree?
Vidpovid
(Let x be the number of pigeons that sat on the tree, and y is the number of pigeons that roamed under the tree. Todi
y - 1 = (x + y) / 3
i, moreover, x - 1 \u1d y + 2, then x \uXNUMXd y + XNUMX.
Substituting x \u2d y + XNUMX y first equal, obsessed
(y - 1) * 3 = y + 2 + y,
3y - 3 = 2y + 2,
y=5.
Also, x = y + 2 = 7.
Otzhe, 7 doves sat on a tree, and 5 doves roamed under the tree)
They knew a dime and gave it away: for men a second copy of a penny, for women a copy, and for children a quarter of a penny. How many people, women and children?
Vidpovid
(One man, five women, fourteen children)
From the numbers 5, 5, 5, 1 and simple arithmetic numbers "+", "-", "*", "/" you need to get the number 24.
Vidpovid
((5-1/5)*5=24)
The Kazkov dwarf needs a new candle, which is to light oneself at the road, wanderers around the city. You can make 1 new candle for 5 candle under-burning. If you get 25 short-lived candles in a new year, then for how many nights you need to make a supply of new candles?
Vidpovid
(For 6 nights. You can make 5 new candles out of 25 under-burning, and if the stink burns, you can get out of 5 under-burning candles, so you can get rid of them)
If my father is 31 years old, I was 8 years old, and now my father is older than me. What are my fates now?
Vidpovid
(23)
She flew grabbing geese, waggling their uncle like that:
- Mabut, there are a hundred of you!
And the geese say:
- "Yakbi us styles,
That would be the style,
That half is like a style,
That quarter is like a stilt,
That you would be with us, - it would be a hundred and bulo.
Skіlki geese?
Vidpovid
(36 гусей: 36+36+18+9+1=100)
Likar Aibolit gave away 2006 miraculous little birds to ill animals. The rhino won by one more, the crocodile lower, the hippopotamus by one more, the lower rhinoceros, and the elephant - by one more, the lower hippopotamus. How many little piglets torment the elephant?
Vidpovid
(503 piglets)
Maєmo cube - black zvonі, ale white in the middle. The height of yogo dorivnyu yogo width and tovshchina and become three likti.
Manager:
1. How many cuts do you need to divide the great cube into small cubes with a size of one cubit?
2. How many cubes will be used after such a rosette?
3. Skіlki z dice will be іz 4 black faces, skіlki - z 3, z 2 and z one only black face?
4. Skіlki vyide small black faces and skіlki vyyde cubes, zovsіm bіlih z usіh boіv?
Vidpovid
(1. You need to cut everything. The skin from the faces of the cube needs a cut of two.
2. There are 27 small cubes in the vide: three balls and in the skin - nine cubes each, placed in a 3 x 3 square.
3. Cubes from chotirm with black faces of the same. From the triple black faces appear those cubes, like virizan from the tops of the great cube. And the cube has all the tops. So that only two black faces appeared at the small cube, which needed to be seen from the middle of the edge of the great cube. So there are twelve small cubes from two black faces. Well, with one black facet, there are 6 cubes.
4. 3 x 3 \u9d 3 small ones come out of the large skin face. And if there were six great faces, then small ones were 3 x 6 x 54 = XNUMX. A cube, which had all sides, could only see one - from the very middle of the great cube)
On the anniversary of Klaus, the goodies were applied with small strokes. Glancing at the yearbook on the sixth year in the afternoon, Klaus revealed that the larger arrow was visible in the small one for 3 gifts.
How many Bulo for the anniversary?
Vidpovid
(At 5.00 a.m., the arrow is streaked in the year 25 hvilinny podіlok. At that moment, when Klaus looked at the anniversary, the old arrow stood in a little more than 3 podіlki th, then, it took 22 podіlok to pass. For 1 min. Luke, and 1/1 is small. .
Otzhe, Klaus looking at the yearbook about 5.24)
On the year of the year exactly 9. Through the skіlki khvilin arrows of the year (khvilinna and the year) run?
If an arrow is worthy before, how insulting the arrows run, it is possible to go through x good things, then a good arrow will pass (45 + x) good things in the same hour. Through those that in one and the same hour the arrow is able to pass 1/12 of that which is hvilinna, we can add up equal x \u45d (12 + x) / 4, stars x \u1d 11 cylinders that (XNUMX/XNUMX).
Vidpovid
(Hvilinna strіlka zbіgaєtsya with the year after 49 qіlih that (1/11) xv)
We are both 63 years old at the same time. At the same time, I’ll have more rocks, what would be the same for you, if there were more rocks of rocks, skils to you at once.
How many fates for me and how many fates for you?
Vidpovid
(At once I'm 36, and you're 27. And if I was 27, and you're 18)
Write in numbers the number that adds up to 11 thousand, 11 hundreds and 11 ones.
Vidpovid
(11000 + 1100 + 11 = 12)
Write 100 five times in singles, and then five five times in fives.
Vidpovid
((111-11), (5+5+5+5)*5 або (5*5*5-5*5))
One biologist discovered a marvelous variety of amoebas. The skin from them through the quill is divided into two. At the test tube, the biologist puts one amoeba, and in a year the whole test tube appears filled with amoeba. How long would it take for the entire test tube to be filled with amoebas, for the yakbees to put not one amoeba, but two, on the cob?
Vidpovid
(59 hwilin)
Once, we passed by and became evidence of an offensive move.
- Chi correctly I you zrozumov? You are strong, that you are a member of the checker's club, you are older, lower.
- Completely correct.
- But how can I remember, having said earlier that I was a member of the checker's club three times more, lower?
- Two fates to that? And yet, my experience as a member of the club is 3 times more than yours, and less than 2 times at a time.
How many fates of the skin from two spivrozmovniki can be a member of the checker's club?
Vidpovid
(Keep tasks and allow you to record equal
(x - the experience of one spіvroznovnik, y - іnshoy):
y=2x,
y - 2x 3 (x - 2),
stars x = 4, y = 8.
Otzhe, one spіvrozmovnik at the checker's club already 8 years, the next - 4 years)
One woman went to the garden to pick an apple. To get out of the garden, it was necessary to go through four doors, with a guard standing at the skin of them. The guards at the first door of the woman gave half of the apples she had picked. After reaching another guard, the woman gave him half of the apples that were gone. So she did it to the third guard; and if the woman shared apples with the guard at the fourth door (with which they made her like that in front), then only 10 apples were left in her. How many apples did she pick in the garden?
Vidpovid
(If x is the number of apples picked by the woman in the garden, then the first guard received x / 2 apples, the other having won x / 4 apples, the third - x / 8 apples and quarters - x / 16 apples. So x / 16 \u10d 160, then x \u160d XNUMX. Later, the woman picked XNUMX apples in the garden)
One zeglina is important for 1 kg and more zeglini piv. How much do you need one zeglin?
Vidpovid
(2 kg)
Before you is viraz 987654321=100. Zrobіt yogo vіrnim, vikoristovuyuchi 4 signs "+" or "-" at yogo lіvіy part.
Vidpovid
(98 - 76 + 54 + 3 + 21 = 100)
The sawyers cut the deck on the meter of the cut. Dovzhina logs 5 meters. Cutting the deck across the board takes about 1,5 hvilin an hour.
How many hours did it take to cut all the decks?
Vidpovid
(Oskіlki, for a podіl 5 meter logs on a meter vіrіzki 4 roses are needed, then 6 khvilin are needed in the whole hour)
Having passed the third way, the passenger of the Swedish train fell asleep. If I had slipped through, to the station of confession, I had to go through half of the dead station, which would have made it up to the station of confession, if I had fallen asleep.
Yaku part way through the train while the passenger slept?
Vidpovid
(So (1/2) * (2/3) \u1d 3/1, the passenger slept 3/XNUMX of the way)
Five diggers for 5 years dig 5 m of a ditch. How many diggers can dig 100 m of ditch in 100 years?
Vidpovid
(5 kopache)
Riba is wonderful to cook from here,
Boiled trout is the king of all dishes.
Accept the request. All is ready. Carry!
Serve in portions of ribey on the table.
Ale scho there for gamir? Then shout the cooks,
"We don't get a table for a portion,
I wouldn’t be able to pay taxes on the table.
I would have left the steel of someone who is called without ribi.
You would not be fooled to name
Us the number of servings of trout
І number of tables
There, de praise the cooks?
Vidpovid
(Let x be the number of portions of ribi prepared by right cooks, y is the number of tables. Todi
y + 1 = x,
2 (y - 1) \uXNUMXd x,
stars y +1 = 2(y - 1), y = 3, x = 4.
Later, the cooks prepared 4 portions of ribi, and 3 tables for the guests)
Sim women went to Rome. In a skin woman, according to these donkeys, a skin donkey, according to this bear, in a skin bear, according to this bread, in a skin bread, according to this knife, and a skin low, according to this bear. How many objects?
Vidpovid
(7^6)
The skeleton climber should stand on the top of a smooth stream of rock with a height of 100 meters. At a height of 50 meters there is a ledge, on which you can grow an intermediate tooth. Skelelas has a skewer with a length of 75 meters. How can I get down from the rocks?
Vidpovid
(It is necessary to make it like this: let’s say a skein for 2 pieces 25 and 50 m, give 25 pieces for the top and rob a loop on the end, let’s put one end of the piece 50 m and connect with another end, we have a bag 50 m itself to the ledge, and going down to the ledge, pulling up the place of the tie 50 m of the tie, rozvyazuemo, fasten behind the ledge and descend)
Skіlki bude: two plus two add to two?
Vidpovid
(3. The first day - a delay, there was no movie about the bows)
Skіlki in me kvіtіv, yakscho all of them okrim two - trojandi, all okrim dvoh - tulips, and all okrim dvoh - daisies?
Vidpovid
(3 (three tickets))
How many faces does a hexagonal olive have?
Vidpovid
(8 faces)
How many times to improve doby hvilinna and year arrows of the year to make a straight kut?
Vidpovid
(For 1 year, an arrow describes a cut of 30 °, and for 1 min. - a cut of 0,5 °. An arrow for 1 min. describes a cut of 6 °. So 90: (6 - 0,5) \u16d 4 (11 / 16), hvilinna th year of the arrows to make a direct kut for the first time after 4 (11/12) hv. 16
Updating dobi hvilinna th year of the arrow to make a straight kut 44 times)
An old problem on a poboot topic. Її asking his teachings the arithmetic teacher Jacob z Coburg, whose assistant was instructed in 1599 p. at Frankfurt.
Vіdstan mіzh 2 places to become 260 miles. From both places nazustrich one goes 2 ginsya to one. One of them can go 2 miles higher, lower one. After 12 days, the gints are zestrichayutsya.
How many miles to pass every day a skin messenger?
Vidpovid
(Let y be the number of miles to travel in one day, and x is the next messenger. Todi
y = x + 2, (1)
12x + 12y = 260. (2)
Substituting (1) in (2), obsessed
12x +12(x+2) = 260,
stars
x = 9 and 5/6.
In this rank, one messenger passing 9 and 5/6 miles in a day, and the other - 11 and 5/6 miles)
The arrows of the yearbook just got off. Through skіlki khvilin stench will "marvel" at the opposite side?
Vidpovid
(Let x - an interval of an hour (at hvilinah), which the first one is guilty of passing, the lower arrows will be drawn on one straight line and will be straightened in the opposite direction. The hvilinna arrow will be able to pass for the whole hour x hvilinnyh podilok of the dial, and the year - x / 12 khvilinnyh podilok . If the arrows are spread out on one straight line and will be straightened in the opposite sides, 30 thin pieces of the dial will be separated.
Otzhe, it's time:
x - x/12 = 30,
stars x = 32 (8/11).
Through 32 (8/11) min. since the arrows run like a hvilinna and a year, the stench will "marvel" at the opposite side)
The total age of members of the family is 4 people are healthy 68, and 4 years ago they are 53. How old are the youngest members of the family?
Vidpovid
(3 rocks)
Targan Valentin voiced, scho vmіє bigati zі swidkіst 50 m / min. They didn’t believe you, and rightly so: in fact, Valentin mixed up everything and thought that there are 60 centimeters in a meter, and 100 seconds for a hvilin. What kind of swedishness (in "normal" m / w) large targan Valentin?
Vidpovid
(Targan Valentin big with swedish 18 m/h)
Three years ago Nastya was 7 times older than her sister Veronica. Two years ago, Nastya was 4 times older than Veronica. Рік ago Nastya bula is 3 times older than Veronica.
Skіlki rokіv Nastya and Veronitsa?
Vidpovid
(Nastі 10 roki, and Veronіtsі 4 roki. Proof: let Nastі x roki at once, and Veronіtsі y. Todi, three roki that could be written down: x-3=7*(y-3), two roka that: x- 2=4*(y-2), right back: x-1=3*(y-1). -3-2=3*(y-2) stars y=2 Substituting the value of y into an equal for x, possessed: x=4*2-4=3)
Three of them played checkers. Usyi played three games. How many party skins?
Vidpovid
(Dvі)
Pet stores sell great and small birds. The great bird is dearer than the small one. The lady who went to the store bought 5 great birds and 3 little ones. Yakby won't buy 3 great birds and 5 small ones, then she would spend 20 dollars less. How many skin birds?
Vidpovid
(The price of a great bird is 20 dollars, and a small one is 10 dollars. Solution: let the price of a small bird be x, then the great one will be y \u2d 5x. The lady bought 5 great ones and three small ones, that is 3y + 3x. 3 small ones, that is 5y + 20x, then I spent $5 less. -> y=3x=3)
I have a penny in two intestines; if from one I transfer one karbovanets, then I will be equal, and if from the other I transfer one karbovanets to the first, then in the first there will be two more, lower in the other. Skіlki in the skin pocket of carbovants?
Vidpovid
(Five and seven)
At the month, three weeks fell on the guys' numbers. Which day of the week of the eighth day of the month?
Vidpovid
(Friday. Weeks fall on numbers: 2, 9, 16, 23, 30)
Indicate five positive numbers, the sum of which is equal to 20, and the additional number is 420.
Vidpovid
(7, 5, 4, 3, 1)
The owner is sitting on a birch bar, overgrown with weeds. Today the number of bur'yanіv podvoyuєєtsya. Winnings are selected for a rozchishchennya, as only half the rate is overgrown. A month later, half the rate was overgrown. How many days does the new one have for cleansing?
Vidpovid
(1 day. Half of the rate is already overgrown)
The hvilinna arrow of a year old can be 2 cm long, and the year is 1,5 cm.
Vidpovid
(Nehai v1 - linear speed of the kіntsa khvilinnoї arrow, and v2 - good. Todi
v1 = s1/t1 = 2pr1/t1 = 2p. 2/1 \u4d XNUMXp cm / year.,
v2 = s2/t2 = 2pr2/t2 = 2p. 1,5/12 \u4d p / XNUMX cm / year.,
v1:v2 = 4p:p/4 = 16:1.
Otzhe, the end of the bad arrow collapses 16 times faster, the bottom end of the old arrow)
The number of three different digits is taken from the number, which is added up from the digits themselves, sorted out in the reverse order. The result is summed up from the quiet of the three numbers themselves, re-stashed anew in a different way. What are the numbers?
Vidpovid
(954 - 459 = 495)
Ferenc Pataky, a wonderful Ugrian estradny counter, who for a few seconds thought to multiply 2 three-digit numbers, speaking in 1979. on TV, demonstrating the offensive trick.
"Multiply your sum by 2, add up to 39, multiply the withdrawn amount by 50, add up to 29, see from the sum of the rivers of your people," Pataki asked. Surprisingly looking at the skin of them, having gained a different number, the first two digits of which mean the number of the same, and the two remaining ones - for the first time, like a calendar rock.
Explain what the focus of Ferenc Pataky is on.
Vidpovid
(For whether there are natural numbers a and b іz admissible multipliers (expansion of cherevikіv and vіk), the sameness is victorious:
[(2a+39) * 50+29] - (1979-b) = 100a+b)
How do you see 15 hvilin, looming under the hand of the 7th 11th dog year?
Vidpovid
(We put one hour of the anniversary on the 7th 11th wind. As soon as the year of the 7th wind is overwhelmed, we turn over yogo. igloo only 11 hvilini), otzhe, vіn vіdmіryає still 4 hvilin, yakі at once from 7 to become 4 hvilin)
How is it necessary to write down the number 3 so that the pouch has 4?
Vidpovid
(3:3+3)
Like three numbers, how to add them up or multiply them to give the same result?
Vidpovid
(1, 2, 3)
If a person goes to work, and then back on a transport, then in general, on the road, it’s stained for the second time. Well, if in obedience in the country of wines on transport, then the whole way is borrowed in a new 30 hvilin. How many hours do people need on the road, like a job and back there will be more money?
Vidpovid
(By means of transport, people stained on the way back 30 khvilin. To that way in one direction, borrow 15 khvilin. Go out, pіshki vin can get to work in 1 year and 30 khvilin - 15 khvilin = 1 year and 15 khvilin. The entire route is borrowed more than an hour - 2 years and 30 hvilin)
How many cocks lay a second egg in a second day, how many two cocks lay in two days?
Vidpovid
(8/3 eggs. The basis of the task lies in the folding of such "speech" like - piv cock, piv eggs, etc.)
All thematic puzzles for adults and children:
- funny puzzles
- Riddles yes/no
- Logic riddles
- Mathematical riddles
- Riddles about household appliances
- Riddles about water, rivers, lakes and seas
- Mysteries about seasons
- Riddles about mushrooms
- Riddles about day and night, time, hours
- Riddles about trees and bushes
- Riddles about wild animals
- Riddles about rain, hail, fog, dew
- Riddles about the house, buildings, furniture
- Riddles about pets
- Riddles about food and drinks
- Riddles about snakes, lizards, snails
- Riddles about tools and tools
- Riddles about kitchen utensils
- Riddles about musical instruments
- Riddles about insects and spiders
- Riddles about vegetables
- Riddles about clothes and shoes
- Riddles about household items
- Riddles about nature
- Riddles about birds
- Riddles about fish and aquatic life
- Riddles about snow, ice, frost
- Riddles about the sun, moon and stars
- Riddles about transport and technology
- Riddles about clouds, thunder and lightning
- Riddles about fruits and berries
- Riddles about flowers and plants
- Riddles about a person
- Riddles about honest and liars
- Riddles about school
- Riddles with a tricky answer
- Riddles with weighings and transfusions
- Riddles with words
- Riddles-jokes
- Kalmyk riddles
- Puzzles for children
- Rebus proverbs and sayings
 See other articles
Section Riddles for adults and children.
Read and write useful comments on this article.
<< Back
 Latest news of science and technology, new electronics:
Artificial leather for touch emulation
15.04.2024
In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>
Petgugu Global cat litter
15.04.2024
Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>
The attractiveness of caring men
14.04.2024
The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>
|
Random news from the Archive Microchip controls muscles
10.06.2012
An organic electronics research team at Linköping University has created a microchip that can control the delivery of the neurotransmitter acetylcholine, allowing for chemical control of muscles.
The new device is based on previously developed transistors that can transport positive and negative ions, as well as biomolecules. Scientists managed to combine both ion channels and conventional microcircuits based on traditional silicon electronics into one transistor.
Thanks to the new technology, scientists can, for example, send chemical signals to muscle synapses where the natural nervous system does not work for some reason. The advantage of chemical control schemes, in particular, with the help of acetylcholine, is the ability to "bypass" the defects of the nerve centers and directly control muscle cells. This does not require attaching a microchip to the nerve endings, which is always associated with great difficulties and rejection problems.
Currently, transistors developed by Swedish scientists are able to control the supply of the signaling substance acetylcholine to individual cells and control muscle contraction. In the future, it is planned to develop chemical chips that can perform complex logical functions. In the future, this may lead to the creation of completely new technologies for the treatment of injuries and chronic diseases by regulating various physiological processes in the body.
|
Other interesting news:
▪ Visa + iPhone
▪ Global warming asymmetry
▪ Brain without immunity
▪ Minibus without a driver
▪ Rugged laptop Gigabyte U4
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ site section Digital technology. Article selection
▪ article All deaths out of spite. Popular expression
▪ article Why does scarlet fever happen? Detailed answer
▪ article Sail on a rubber boat. Personal transport
▪ article Mains voltage indicator. Encyclopedia of radio electronics and electrical engineering
▪ article Reflection of sound. physical experiment
Leave your comment on this article:
 All languages of this page
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua
2000-2024
|
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese