55+ Math Riddles for All Ages: Easy, Hard & Funny Problems

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Mathematics Educator Zina Savva explains how to solve even the trickiest riddles

Co-authored by Zina Savva and Hunter Rising

Last Updated: March 11, 2026 Fact Checked

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• Easy Math Riddles for Kids
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• Hard Math Riddles for Adults
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• Funny Math Riddles
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• Challenging Math Brain Teasers
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• Tips

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If you’re looking for a fun way to sharpen up your math skills, then solving riddles is an excellent way to test your knowledge. Riddles can help you set up and understand tougher math concepts, and we’ve got a perfect variety for you to solve. Keep reading for easy, challenging, and funny math riddles and brain teasers, along with hints and explanations to help you out if you get stuck. (Scroll slowly to read each riddle so you don't reveal the answer too soon!)

Pro Tips for Solving Math Riddles

Mathematics Educator Zina Savva says logic and persistence are the keys to solving math riddles. First, make sure you understand what the riddle is asking. Break the problem down into smaller parts, look for patterns, and experiment with different ways to solve the riddle. Some of Savva's favorite riddles include:

• The nine dots riddle, which forces you to think outside the box, literally!
• The riddle of 1000 prisoners, which requires fundamental knowledge of square numbers.
• The Monty Hall problem, which challenges your intuition as well as logic.
• The 11 castaways riddle, which involves a simple question that's deceptively hard to answer.

Steps

Section 1 of 4:

Easy Math Riddles for Kids

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1. 
   1
   A grandfather, 2 fathers, and 2 sons went to the zoo together and each person bought a ticket. How many tickets did they buy in total? Answer: 3 tickets

   • Explanation: The grandfather also counts as a father, and the father also counts as a son.
2. 2
   There are 6 apples on the table. If you take 2 away, how many apples do you have? Answer: 2 apples.

   • Explanation: The question asks how many apples “you” have, not how many apples are left on the table.
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3. 3
   What can you put between 3 and 7 to make a number larger than 3 but smaller than 7? Answer: A decimal point (3.7)
4. 4
   A family has 5 sons. Each son has a sister. How many children are in the family? Answer: 6 children

   • Explanation: There are 5 sons and 1 daughter. The sons all share the same sister.
5. 
   5
   How many 9s are there between 1 and 100? Answer: 20 (9, 19, 29, 39, 49, 59, 69, 79, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, and 99)
6. 6
   How do you make 1,000 only using addition and the number 8? Answer: 888 + 88 + 8 + 8 + 8 = 1,000
7. 7
   I am a 3-digit number. My second digit is four times bigger than my first and last digit. My first digit is three less than my second digit. What am I? Answer: 141
8. 8
   What 3 positive numbers can be added or multiplied together and you would get the same result? Answer: 1, 2, and 3
9. 9
   Is it cheaper to take 2 friends to the movie at the same time, or 1 friend to the same movie twice? Answer: 2 friends at the same time

   • Explanation: If you take 2 friends at the same time, you only pay for 3 tickets. If you go with the same friend twice, then you’d buy a total of 4 tickets.
10. 
    10
    How do you use four 9s to make 100? Answer: 99 + (9/9) = 100
11. 11
    There are 2 ducks in front of 2 other ducks, and there are 2 ducks behind 2 other ducks. There are also 2 ducks standing next to 2 other ducks. How many ducks are there in total? Answer: 4 ducks

    • Explanation: The ducks are arranged in a 2 x 2 square.
12. 12
    If Bobby flips a coin 5 times and it lands on heads each time, what are the chances of landing on tails on the next flip? Answer: 50%

    • Explanation: There’s always a 50/50 chance of heads or tails when you flip a coin, no matter what the previous results were.
13. 13
    If eggs are $0.12 per dozen, how many eggs can you get for $1? Answer: 100 eggs

    • Explanation: If there are 12 eggs in a dozen, that means each egg only costs $0.01. There are 100 cents in a dollar, so you can buy 100 eggs.
14. 14
    If you multiply this number by any other number, the answer will be the same. What number is it? Answer: 0
15. 
    15
    How can you write a correct math equation only using 2, 3, 4, and 5 and addition? Answer: 2 + 5 = 3 + 4
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Section 2 of 4:

Hard Math Riddles for Adults

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1. 
   1
   If 8 people are meeting and each person shakes hands once with each of the others, how many handshakes were there? Answer: 28 handshakes

   • Explanation: The first person shakes hands with 7 people, the next person shakes hands with the next 6 people, and so on, so 7 + 6 + 5 + 4 + 3 + 2 + 1 = 28
2. 2
   If pants cost $20 more than a shirt, and the total cost of both items is $70, how much does each item cost? Answer: The shirt is $25 and the pants are $45.

   • Explanation: Use x as the cost of the shirt and x + 20 as the cost of the pants. Simplify the equation x + x + 20 = 70 to find your answer.
3. 3
   A mother is 4 times as old as her daughter. In 20 years, she will be twice as old as her daughter. How old are they now? Answer: The mother is 40 and the daughter is 10.

   • Explanation: Use x as the daughter’s age. The mother’s age would be 4x. If in 20 years the mother is twice the daughter’s age, use the equation 2(x + 20) = 4x + 20 and solve for x.
4. 4
   There are 10 pairs of dogs, and each dog has 2 pairs of puppies. If 15 of the puppies are adopted, how many dogs are left? Answer: 85 puppies

   • Explanation: Each dog in the original 10 pairs has its own puppies, so 20 dogs have 4 puppies each, for a total of 80 puppies. 20 dogs + 80 puppies - 15 adopted puppies = 85 dogs leftover.
5. 
   5
   There are a few cards missing from a standard 52-card deck. When you deal the entire deck out to 4 people, there are 3 cards leftover. If you deal the entire deck out to 3 or 5 people, there are 2 cards leftover. How many cards are missing? Answer: 5 missing cards

   • Explanation: Subtract the number of missing cards from the total number in the deck, and then divide the result by 3, 4, and 5 to check the remainders. With 5 cards missing, a group of 3 people each get 15 cards (2 left over), a group of 4 each get 11 cards (3 left over), and a group of 5 each get 9 cards (2 left over).
6. 6
   If you divide 30 by ½ and then add 5, what is the result? Answer: 65

   • Explanation: When you divide a number by ½, you actually multiply it by the reciprocal, which is 2. (30 x 2) + 5 = 65.
7. 7
   If 2 + 2 = 44, 3 + 3 = 96, and 4 + 4 = 168, what does 5 + 5 equal? Answer: 2,510

   • Explanation: The answers to each equation are the numbers multiplied together combined with the numbers added together (5 x 5 = 25 and 5 + 5 = 10 for a final result of 2510).
8. 8
   How can you make 5 + 5 + 5 = 550 true by adding a single line? Answer: Draw a diagonal line connecting the left and top points on the first plus sign to change it into a 4 so it reads 545 + 5 = 550.
9. 9
   The combined age of a father and son are 66. If the father’s age is the son’s age reversed, and the son is a teenager, how old are they both? Answer: The father is 51 and the son is 15.

   • Explanation: Find the pairs of numbers with reversed digits that add up to 61 (06 & 60, 15 & 51, and 24 & 42). Only one of these pairs has a number in the teens, so they must be 15 and 51.
10. 
    10
    A quarter of the animals on a farm have 4 legs, and the other 3 quarters have 2 legs. If there are 60 legs total, how many animals are on the farm? Answer: 24

    • Explanation: If X is the number of 4 -legged animals and Y is the number of 2-legged animals, then use the equation (x • 4) + (y • 2) = 60.
    • The equation simplifies to 4x + 2y = 60
    • You also know that X is ¼ and Y is ¾ of the total animals, then y = 3x.
    • Substitute 3x in for Y, so the equation reads 4x + 2(3x) = 60 → 4x + 6x = 60 → 10x = 60.
    • Divide each side by 10 to solve for X, so x = 6.
    • Plug in the value of X to the original equation to solve for Y. 4(6) + 2y = 60 → 24 + 2y = 60 → 2y = 36 → y = 18.
    • There are 6 animals with 4 legs, and 18 animals with 2 legs.
11. 11
    There are 12 students total. 6 students are wearing socks, 4 students are wearing shoes, and 3 students are wearing both. How many students are barefoot? Answer: 5 students

    • Explanation: Out of the 12 students, 3 of them are wearing socks and shoes, 3 more are wearing just socks, and 1 more is wearing only shoes, leaving 5 students barefoot.
12. 12
    In an alien world, ½ of 5 equals 3. Using the same proportions, how much is ⅓ of 10? Answer: 4

    • Explanation: If ½ of 5 equals 3, then 5 = 2 x 3 = 6. In this case, 10 = 2 x 6 = 12. Divide 12 by 3 to get the final answer of 4.
13. 
    13
    Abe weighs half as much as Bill, and Caleb weighs 3 times as much as Abe. If their total weight is 720 pounds, how much do they each weigh? Answer: Abe weighs 120 pounds, Bill weighs 240 pounds, and Caleb weighs 360 pounds.

    • Explanation: Use X for Bill’s weight to set up the formula ½x + x + 1½x = 720.
    • Add the values to simplify the equation to 3x = 720.
    • Divide by 3 to solve for X, so X = 240.
    • Then, plug the value of X into each weight to find the values.
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Section 3 of 4:

Funny Math Riddles

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1. 
   1
   How many sides does a circle have Answer: 2, the inside and the outside!
2. 2
   If you buy a rooster to lay eggs and expect 3 eggs every day, how many eggs will you have after 2 weeks? Answer: None, roosters don’t lay eggs.
3. 3
   If you multiply all the numbers on a telephone together, what number do you get? Answer: 0

   • Explanation: Anything multiplied by 0 equals 0.
4. 4
   How do you make 7 even without adding, subtracting, multiplying, or dividing? Answer: Take the letter “S” off the word “seven,” and you’re left with “even.”
5. 
   5
   There are 2 coins that equal 30 cents, and one of them is not a nickel. What are the coins? Answer: A quarter and a nickel.

   • Explanation: The riddle only says that one coin is not a nickel, but the second coin can still be a nickel.
6. 6
   If 2 is a couple and 3 is a crowd, what is 4 and 5? Answer: 9

   • Explanation: This trick question is asking you to add the numbers 4 and 5, which equals 9.
7. 7
   It takes 6 people 8 hours to build a barn. How long does it take 12 people to build the same barn? Answer: None, the barn is already built!
8. 8
   A butcher is 6 feet tall and he has size 10 feet. What do they weigh? Answer: Meat, because they work in a butcher shop.
9. 9
   How did the football fan know before the game that the score would be 0-0? Answer: The score is always 0-0 before the game starts.
10. 
    10
    How many bricks does it take to finish a brick building? Answer: One

    • Explanation: While there are multiple bricks in a building, only the last one that’s placed is needed to finish the building.
11. 11
    A man going to the museum passes 4 women each holding 4 baskets. In each basket, there are 4 cats. How many total creatures are going to the museum? Answer: One

    • Explanation: Only the man is going to the museum. He passed the women and cats on his way there.
12. 12
    What weighs more, 1 pound of feathers or 1 pound of bricks? Answer: Neither, they weigh the same.
13. 13
    If it’s raining at midnight but the forecast is clear for tomorrow and the next day, will the sun be out in 48 hours? Answer: No

    • Explanation: Even if the weather is clear, in 48 hours it will be midnight and dark again.
14. 14
    What is a math teacher’s favorite dessert? Answer: Pi(e)
15. 
    15
    What did one math textbook say to the other? Answer: I have a lot of problems!
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Section 4 of 4:

Challenging Math Brain Teasers

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1. 
   1
   How many times can you subtract 5 from 25? Answer: Once

   • Explanation: After you subtract 5 the first time, then it becomes 20, not 25.
2. 2
   How can you add 4 to 11, and get 3? Answer: If a clock reads 11 AM and you add 4 hours, then it will be 3 PM.
3. 3
   How can you take 2 from 5 and leave 4? Answer: If you take the first and last letter from the word “five” you’re left with “IV” (4 in Roman numerals).
4. 4
   How can you make the equation 81 x 9 = 801 true? Answer: Flip it upside-down (108 = 6 x 18).
5. 
   5
   If 3 men can make 3 chairs in 3 hours, how many chairs can 6 men make in 6 hours? Answer: 12 chairs
6. 6
   If a 200-foot train going 200 feet per minute travels through a 200-foot tunnel, how long does it take for the train to travel through it completely? Answer: 2 minutes

   • Explanation: The front of the train takes 1 minute to pass through the tunnel and the rest of the train takes another minute to exit the tunnel.
7. 7
   If one is three, three is five, five is four, and four is the magic number, what is the pattern? Answer: The second number is how many letters are in the word. Because the word “four” is the only value that matches the number of letters in the word, it’s the magic number.
8. 8
   If a vest costs $28, a sweater costs $49, and pants cost $35, how much do underwear cost? Answer: $63

   • Explanation: Each item costs $7 for each letter in the word.
9. 9
   In 1990, a person celebrated their 15th birthday. In 1995, the same person celebrated their 10th birthday. How is this possible? Answer: The years are in BCE, so 1995 BCE is 5 years earlier than 1990 BCE.
10. 
    10
    When Mary was 5, she hammered a nail into a tree 40 inches from the ground to mark her height. If Mary comes back when she’s 15 and the tree grows 5 inches every year, how much higher is the nail? Answer: The nail is in the same place.

    • Explanation: Trees grow from the top, so the nail doesn’t change positions.
11. 11
    How can someone pass away from old age if they’re only 25? Answer: Their birthday is on February 29th, so they only celebrate every 4 years on a leap year.
12. 12
    If you double a number and multiply it by 4, and then divide the result by 8, you’ll have the original number. What number is it? Answer: Any number

    • Explanation: When you double a number and then multiply by 4, you’re actually multiplying the original number by 8. Dividing by 8 will always bring you back to the original number.
13. 13
    One child leaves for school and another child leaves 15 minutes later. Both children cross each other in the school parking lot. Which child is closer to the school? Answer: Both children are the same distance from the school.

    • Explanation: The question doesn’t ask which child lives closer, but which one is closer now. Both children are in the parking lot at the same time, so they’re the same distance.
14. 14
    If you caught 20 ants and all but 7 of them escaped, how many ants are left? Answer: 7
15. 
    15
    You have an empty box with a 1-foot diameter and 1-foot depth. How many 3-inch oranges can be put inside the empty box? Answer: One

    • Explanation: After you put in the first orange, the box won’t be empty anymore.
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Tips

• Ronnie Libedinsky, an academic tutor, recommends breaking word problems into sections to understand them easier. As you read through the problem, think about what mathematical functions to use and write out an equation.
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