Shiver me timbers, it’s math! Isn’t it horrible!? There there, calm down; these math riddles are, in fact, much more fun than solving some horrendous algebra problem or trying to figure out train times and the length of your voyage. This is the fun kind of math, where you have to base your answers on logic and critical thinking - if only it were the same at school, right? Anyway, ready to get started on solving these entertaining math riddles? Well, ready or not, this is our compendium of algebra riddles that might just blow you away.
These fun riddles are all supplied with their answers, so you won’t have to google for it or call your dad for help if you get stuck. But, of course, looking at them straight away would spoil all that fun only math can give you! So, don’t do that to yourself and try solving these pretty easy riddles first. You know what else might be fun? Sharing these cool riddles with your friends and trying to solve them simultaneously, timing who gets the correct answer first! Now, doesn’t that sound fun?
Okay, no need to contain the excitement any longer - just scroll on down below and check the smart riddles out! Once you are there, vote for the math riddles that have tickled your fancy, and as discussed before, share this article with your friends for optimum fun.
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What number do you get when you multiply all of the numbers on a telephone’s number pad?
Oooh nice!! I actually started multiplying in my head for a second, too
Where can you add 2 to 11 and get 1?
A duck was given $9, a spider was given $36, a bee was given $27. Based on this information, how much money would be given to a cat?
A bat and a ball cost $1.10. The bat costs one dollar more than the ball. How much does the ball cost?
Can you arrange four nines to make it equal to 100?
When John was six years old, he hammered a nail into his favorite tree to mark how tall he was. Ten years later at age sixteen, John returned to see how much higher the nail was. If the tree grew by five centimeters each year, how much higher would the nail be?
When Josh was 8, his brother was half his age. Now that Josh is 14, how old is his brother?
When my father was 31 and I was 8. Now he is twice as old as me. How old am I?
Answer: The difference in age is 23 years, so I must be 23 if my father is twice as old as me.
How many sides does a circle have?
What single digit appears most frequently between and including the numbers 1 and 1,000?
Hint: look for a pattern!
You are given 3 positive numbers. You can add these numbers and multiply them together. The result you get will be the same. Which are the numbers?
What is the next number in the series? 7,645 5,764 4,576
Answer: 6,457 because the last number is moved to the front to make the next number in the series.
Add me to myself and multiply by 4. Divide me by 8 and you will have me once more. What number am I?
If you multiply this number by any other number, the answer will always be the same. What number is this?
The day before yesterday I was 21, and the next year, I will be 24. What day is my birthday?
I had to pull out a calandre to go through the answers steps
Nathan has 8 bricks. Seven of them weigh the same amount and one is slightly heavier. Using a balance scale, how can Nathan find the heavier brick in two weighings?
Old Granny Adams left half her money to her granddaughter and half that amount to her grandson. She left a sixth to her brother, and the remainder, $1,000, to the dogs’ home. How much did she leave altogether?
What can you put between a 7 and an 8 so that the result is greater than a seven, but less than an eight?
If you’re 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?
If there are 4 apples and you take away 3, how many do you have?
When Mitch was 6 years old, his little sister, Lila, was half is age. If Mitch is 40 years old today, how old is Lila?
Sally and Sarah were preparing to have a water balloon fight. “No Fair” cried Sally, “You have 3 times as many as I do!” Sarah said “Fine!” and gave Sally 10 more balloons. “Still not fair!” argued Sally, “You still have twice as many as I do.” How many more balloons must Sarah give Sally for them to have the same number?
Answer: Sarah must give Sally another 20 water balloons, giving them each 60. Sally started with 30 water balloons and Sarah with 90.
In a pond, there are some flowers with some bees hovering over them. How many flowers and bees are there if both the following statements are true: If each bee lands on a flower, one bee doesn’t get a flower. If two bees share each flower, there is one flower left out.
If it were two hours later, it would be half as long until midnight as it would be if it were an hour later. What time is it now?
If you go to the movies and you’re paying, is it cheaper to take one friend to the movies twice or two friends to the movies at the same time?
Which month has 28 days?
What number goes up and doesn’t come back down?
If you buy a rooster for the purpose of laying eggs and you expect to get three eggs each day for breakfast, how many eggs will you have after three weeks?
And even if it was a hen, you'd still have none, because you are them all at breakfast.
If two’s company and three’s a crowd, what are four and five?
What is the smallest number that increases by 12 when it is flipped and turned upside down?
In an odd little town, was an odd little stream, with odd little fish in an odd little team. A stranger approached a local fisherman and asked him how much his odd little fish weighed. The odd little man replied, “All the fish in this stream weigh exactly 1/2 of a pound plus 1/2 of a fish. Isn’t that odd?” How many pounds does an odd little fish weigh?
A man is twice as old as his little sister. He is also half as old as their dad. Over a period of 50 years, the age of the sister will become half of their dad’s age. What is the age of the man now?
How can you make the following equation true by drawing only one straight line: 5+5+5=550 Can you figure it out?
Answer: There are two ways to do so: Draw a line on the first plus sign to turn it into a 4. Change the equal symbol to a crossed-out equal symbol which means “not equal to.”
A man is walking down a street night at a constant pace. As he passes the street light, he notices that his shadow becomes longer. Does the top of his shadow move faster, slower, or the same when the shadow is longer than when it is shorter?
I am four times as old as my daughter. In 20 years, I shall be twice as old as her. How old are we now?
If eggs are $0.12 a dozen, how many eggs can you get for a dollar?
A farmer has 17 sheep and all but 9 die. How many are left?
You know 2 + 2 comes to the same as 2 x 2. Now find a set of three different whole numbers whose sum is equal to their total when multiplied.
A 300 ft. train is traveling 300 ft. per minute and must travel through a 300 ft. long tunnel. How long will it take the train to travel through the tunnel?
Answer: Two minutes because it takes the front of the train one minute and the rest of the train will take two minutes to clear the tunnel.
If you place three matches on a table then tell a friend to add two more matches to make eight, how can he do so?
Answer: Make a Roman numeral five out of two matches and add it to the three to make a Roman numeral eight.
If X is an odd number, when a letter is taken away from X and it becomes even. Which is that number?
If seven people meet each other and each shakes hands only once with each of the others, how many handshakes will there have been?
How can you take 2 from 5 and leave 4?
Answer: Remove the 2 letters F and E from the word FIVE and you have IV.
Once I’m 24. Twice I’m 20. Three times I’m inappropriate. What am I?
Anna wrote all the numbers from 300 to 400 on a piece of paper. How many times did she write the digit 3?
I am a number with a couple of friends, quarter a dozen, and you’ll find me again. What am I?
I am a three-digit number. My tens digit is five more than my one’s digit. My hundreds digit is eight less than my tens digit. What number am I?
There are several books on a bookshelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?
There are two ducks in front of two other ducks. And, there are two ducks behind two other ducks. There are two ducks beside two other ducks. How many ducks are there?
Tom was asked to paint the apartment number on plates for 100 apartments which means he will have to paint numbers 1 through 100. How many times will he paint the number 8?
Answer: 20 times (8, 18, 28, 38, 48, 58, 68, 78, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 98).
My twin lives at the reverse of my house number. The difference between our house numbers ends in two. What are the lowest possible numbers of our house numbers?
Answer: These math riddles aren’t easy to solve! The lowest possible numbers for the houses are 19 and 91. The difference is 72.
Three friends are on a road trip, and they rent a triple room for a night. When they get to the hotel, they pay the fee of $30 and go up to their room. The porter brings up their bags and refunds them $5 because the hotel is running a weeknight special. The three friends each keep one of the dollars and give the porter a $2 tip. Later, they sit down to work out their expenses for the weekend and find they have a problem. They each paid $10 for the room and got $1 back each, making their contributions $9. Then they gave the porter a $2 tip. However, 9 times three is 27, plus two is $29. Where did the extra dollar go?
Answer: This one is a bit twisty, but what it boils down to is that the three friends’ math is wrong. They didn’t spend $29, they spent $27: $25 on the room, and $2 for the porter’s tip. The three remaining dollars were returned to them!
I am a three-digit number. My second digit is 4 times bigger than the third digit. My first digit is 3 less than my second digit. What number am I?
If the zookeeper had 100 pairs of animals in her zoo and if two pairs of babies are born for each and every one of the original animals, and then sadly 23 animals don’t survive, how many animals do you have left in total?
Answer: 977 animals (100×2 = 200; 200+800 = 1000; 1000-23 = 977).
How many times does the long hand of the clock pass the short hand between midnight one day and midnight the following day? As both hands are together at the starting time of midnight this does not count as a pass.
You go to the doctor because you are ill, and he prescribes you with three pills and tells you to take them every half hour. How long do the pills last you?
Answer: An hour because the first pill doesn’t take 30 minutes to take.
An apple is 40 cents, a banana is 60 cents. and a grapefruit is 80 cents. How much is a pear?
Answer: Forty cents, because the price of each fruit is calculated by multiplying the number of vowels by 20 cents.
Harry is 54 years old, and his mother, Anna, is 80. How many years ago was Anna three times the age of her son Harry?
John, Mark, and Henry are three brothers. Interestingly, their current age is prime. What’s more interesting is that difference between their ages is also prime. How old are they?
Answer: Mark is 2, John is 5, and Henry is 7. Age diff 7 – 2 = 5 is prime; 7 – 5 = 2 is prime; 5 – 2 = 3 is prime.
Joe has ten coins totaling $1.19. From these coins, he cannot make exact change for a dollar, half-dollar, quarter, dime, or nickel. What coins does he have?
Answer: A half-dollar, a quarter, four dimes, and four pennies.
There are twelve kids in a classroom. Six kids are wearing socks and 4 are wearing shoes. Three kids are wearing both. How many have bare feet?
There are 25 red balls, 47 green balls. and 3 blue balls in a basket. There is a blind man. What is the minimum number of balls that the blind man has to pick to make sure that there are at least 2 balls of different colors?
Answer: 48 balls. There is a small chance he may pick up 47 green balls in a row.
Two travelers spend from 12 o’clock to 6 o’clock walking along a level road, up a hill, and back again. Their pace is 4 mph on the level, 3 mph uphill, and 6 mph downhill. How far do they walk and at what time do they reach the top of the hill?
With no indication of how long the stretches of road are to each other, the time is between 3 an 4 o'clock: with 3 being smallest hill and 4 being largest hill.
Two people in front of two people, two people behind two people, and two people beside two people. How many people are there?
Janie’s friends were chipping in to buy her a wedding shower present. At first, 10 friends chipped in, but 2 of them dropped out. Each of the 8 had to chip in another dollar to bring the amount back up. How much money did they plan to collect?
What is the value of 1/2 of 2/3 of 3/4 of 4/5 of 5/6 of 6/7 of 7/8 of 8/9 of 9/10 of 1000?
You have two U.S. coins with a total value of 30 cents. One of them is not a nickel. What are the two coins?
How can you add eight fours together so the total adds up to 500?
If it took 6 people 9 hours to build a barn, how long would it take 12 people to build the same barn?
What is the maximum possible number of times you can subtract number 5 from number 25?
Answer: Only once, is because when you subtract 5 from 25, it becomes number 20, then 15, etc.
Using only addition, add eight 8s to get the number 1,000.
One brother says of his younger brother: “Two years ago, I was three times as old as my brother was. In three years’ time, I will be twice as old as my brother.” How old are they each now?
Answer: One way to solve this math riddle is to use even numbers: The older brother will be twice as old as his younger brother in three years’ time. This immediately rules out the older brother currently being 8, 11, and 14, so he must be 17, and the younger brother 7. Two years ago, they were 15 and 5 respectively, and in three years’ time, they will be 20 and 10.
I add six to eleven, and get five. Why is this correct?
Answer: This numbers riddle is designed to trip you up! You have to think more broadly. When it is 11 a.m., adding six hours makes it 5 p.m.
If a hen and a half lay an egg and a half in a day and a half, how many eggs will half a dozen hens lay in half a dozen days?
A small number of cards has been lost from a complete pack. If I deal among four people, three cards remain. If I deal among three people, two remain and if I deal among five people, two cards remain. How many cards are there?
Answer: This one is pretty tricky, but the answer is: There are 47 cards. To get the answer, you need to know that there are 52 cards in a pack. Then, find the multiples of four, three, and five closest to that number, and see if any of them are the same. For example, you can deal 42, 44, and 48 cards amongst four people, which would mean 9, 5, or 1 cards is missing (with three remaining). However, the only one that works for multiples of three and five people is when five cards are missing, which gives us a total of 47 cards.
Mrs. Jones was very proud of her apple tree. One autumn, after harvesting her apples, she called her three sons together. “Here are 150 apples,” she said. “I want you to take them to the market tomorrow and sell them for me.” She gave Paul 15 apples, Nick 50, and Ben 85. “Your job,” added Mrs. Jones, “is to sell the apples in such a way that each of you brings home the same amount of money.” How do they do it?
Answer: The first buyer purchases 12 dozen apples at $1 per dozen. Paul sells him one dozen and has three apples left; Nick sells him four dozen and has two apples left; and Ben sells him seven dozen and has one apple left. Then a second buyer comes along and buys all their remaining apples for $3 apiece. The three brothers head home with $10 each.
What is the smallest whole number that is equal to seven times the sum of its digits?
Answer: The answer to this math riddle is 21. You probably just guessed to answer this math riddle, which is fine, but you can also work it out algebraically. The two-digit number ab stands for 10a + b since the first digit represents tens and the second represents units. If 10a + b = 7(a + b), then 10a + b = 7a + 7b, and so 3a = 6b, or, more simply, a = 2b. That is, the second digit must be twice the first. The smallest such number is 21.
John noticed that the amount he was paying for his lunch was a rearrangement of the digits of the amount of money he had in his pocket, and that the money he had left over was yet another rearrangement of the same three digits! How much money did John start with?
Answer: John started with $9.54. The money can be written with just three digits, so it must be between $1.01 and $9.99. Trial and error shows that there is only one set of numbers that fits this question: $9.54 = $4.59 + $4.95.
A grandmother, two mothers, and two daughters went to a baseball game together and bought one ticket each. How many tickets did they buy in total?
Answer: Three tickets because the grandmother is the mother of the two daughters who are mothers.
Tom is in charge of shipping and he can place 10 small boxes or 8 large boxes into a carton. A total of 96 boxes were sent in one shipment. The number of small boxes was less than large boxes. What is the total number of cartons he shipped?
Answer: 11 cartons If a total of 96 boxes are shipped, then the large boxes in the cartons must be a multiple of 8, which means either 16 or 56 large boxes. Since there are more large boxes in the cartons then the small ones, the number of large boxes must be 56. The number of small boxes is reduced to 96 – 56 = 40. Therefore, the total number of cartons shipped can be figured out this way: 56/8 + 40/10 = 7 + 4 = 11.
I add five to nine and get two. The answer is correct, but how?
There is a clothing store in Smithville. The owner has devised his own method of pricing items. A vest costs $20, socks cost $25, a tie costs $15 and a blouse costs $30. Using the method, how much would a pair of underwear cost?
Answer: $45 because the pricing method consists of charging $5 for each letter required to spell the item.
In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it take for the patch to cover half the lake?
Answer: The patch doubles in size every day and so on the 47th day the patch will be half the size it is on the 48th day.
How many days are there in 4 years?
Answer: The answer is 1461, because (365 x 4) + 1. One of the years is a leap year.
You have accidently left out the plug and are attempting to fill the bath with both taps full on. The hot tap takes 6 minutes to fill the bath. The cold tap takes 2 minutes and the water empties through the plug hole in 4 minutes. In how many minutes will the bath be filled?
A nonstop train leaves Moscow for Leningrad at 60 mph. Another nonstop train leaves Leningrad for Moscow at 40 mph. How far apart are the trains 1 hour before they pass each other?
I asked a girl how old she was. She said, “In 2 years I will be twice as old as I was 5 years ago.” How old is she?
A cellphone and a phone case cost $110 in total. The cell phone costs $100 more than the phone case. How much was the cellphone?
If 9999 = 4, 8888 = 8, 1816 = 6, 1212 = 0, then 1919 = ?
The multiply by #of other digest would make 9999 and 8888 also 0, because there are no other digests...
If you can purchase 8 eggs for 26 cents, how many can you buy for a cent and a quarter?
What did the triangle say to the circle?
I have a calculator that can display ten digits. How many different ten-digit numbers can I type using just the 0-9 keys once each, and moving from one keypress to the next using the knight’s move in chess? (In chess, the knight moves in an L shape: one square up and two across, two squares down and one across, two squares up and one across, and other like combinations.)
Answer: You can form the numbers 5034927618 and 5038167294. You can also form their reverses: 8167294305 and 4927618305. Hence four different numbers can be made. The key point is to realize that the number must start or end on the “5” key, followed/preceded by the ‘0’ key, otherwise, there is no way of using all ten keys during the route.
I am a three-digit number. My tens digit is six more than my one’s digit. My hundreds digit is eight less than my tens digit. What number am I?
Divide 20 by half and add 30, what do you get?
In reply to an inquiry about the animals on his farm, the farmer says: “I only ever keep sheep, goats, and horses. In fact, at the moment they are all sheep bar three, all goats bar four, and all horses bar five.” How many does he have of each animal?
Answer: The farmer has 3 sheep, 2 goats, and 1 horse. You can solve this easy math riddle with a quick hypothetical. Take sheep: we know that there are three animals that are goats and horses, so we suppose there are two goats and one horse. Checking this hypothesis gives us three sheep, which works out because there are four non-goats: three sheep, and one horse!
Leon works at the aquarium. When he tries to put each turtle in its own tank, he has one turtle too many. But if he puts two turtles per tank, he has one tank too many. How many turtles and how many tanks does Leon have?
This one is either badly worded, badly translate or just wrong. As my maths shows U=turtle and K=tank U-1=k and t/2=k-1 So rearrange the first for u=k+1 and the second for u=2*k-2 So k+1=2*k-2 rearrange to 1+2=2k-k or 3=k Put that in the first equation you get u=3+1=4 so you get 4 Turtles and 3 tanks
A certain number has three digits. The sum of the three digits equals 36 times this number. Seven times the left digit plus 9 is equal to 5 times the sum of the two other digits. 8 times the second digit minus 9 is equal to the sum of the first and third. What is the number?
The sun of 2, 3, and 4 is actually not equal to 36 times 324. I understand what you're trying to say, but... No
A lot of these are not very good and some aren't actually riddles, just math.
I wish these were laid out on a better format so I could see the question without accidentally skimming the answer. A single line break would have been so helpful.
A lot of these are not very good and some aren't actually riddles, just math.
I wish these were laid out on a better format so I could see the question without accidentally skimming the answer. A single line break would have been so helpful.
