Looking for a fun way to stretch your mental muscles? This ultimate guide of math riddles is perfect for those who love a challenge.
With 355 carefully selected riddles, you’ll engage your brain, boost your problem-solving skills, and maybe even share a laugh with friends. Let’s dive into the world of mathematical puzzles!
Classic Math Riddles
- Riddle: What comes once in a minute, twice in a moment, but never in a thousand years?
Answer: The letter “M.” - Riddle: I am a three-digit number. My tens digit is five more than my ones digit, and my hundreds digit is eight less than my tens digit. What number am I?
Answer: 194. - Riddle: If two’s company and three’s a crowd, what are four and five?
Answer: Nine. - Riddle: The ages of a father and son add up to 66. The father’s age is the son’s age reversed. How old are they?
Answer: 51 and 15, or 60 and 6. - Riddle: I add five to nine and get two. The answer is correct, but how?
Answer: When it is 9 AM, adding 5 hours makes it 2 PM. - Riddle: What is the next number in the series: 2, 3, 5, 9, 17, __?
Answer: 33 (the pattern is doubling the previous difference). - Riddle: A man is 30 years old in 2000, but in 2010, he turns 20. How is this possible?
Answer: He was born in 2020 B.C. - Riddle: When does 11 + 2 equal 1?
Answer: On a clock, 11 o’clock + 2 hours = 1 o’clock. - Riddle: Two fathers and two sons went fishing. They all caught one fish, but there were only three fish. How?
Answer: There was a grandfather, father, and son. - Riddle: How many sides does a circle have?
Answer: Two – inside and outside.
Geometry and Shape Riddles
- Riddle: What 3D shape has faces shaped like triangles and vertices where five faces meet?
Answer: An icosahedron. - Riddle: I have four sides, all of which are equal, and my angles are right. What am I?
Answer: A square. - Riddle: What shape has the same number of faces and vertices?
Answer: A tetrahedron. - Riddle: What kind of triangle has one angle greater than 90 degrees?
Answer: An obtuse triangle. - Riddle: You see a pentagon with no straight lines in front of you. What are you looking at?
Answer: A circle. - Riddle: What polygon has the fewest sides?
Answer: A triangle. - Riddle: What is the sum of all angles inside a pentagon?
Answer: 540 degrees. - Riddle: What shape has no volume and a circumference but no corners?
Answer: A circle. - Riddle: What is the name of a 10-sided polygon?
Answer: A decagon. - Riddle: What’s smaller than a house, bigger than a car, and has four sides but no right angles?
Answer: A trapezoid.
Number Riddles
- Riddle: I am an odd number. Take away one letter, and I become even. What number am I?
Answer: Seven. - Riddle: What number is half of two-thirds of a hundred?
Answer: 33.33. - Riddle: What is the only number that is twice the sum of its digits?
Answer: 18. - Riddle: What number comes next in the series: 1, 4, 9, 16, 25?
Answer: 36 (squares of numbers: 1², 2², 3², 4², 5², 6²). - Riddle: What number is neither prime nor composite?
Answer: 1. - Riddle: I am a two-digit number. The sum of my digits is 12, and the difference is 4. What number am I?
Answer: 48. - Riddle: What number is the sum of the first four prime numbers?
Answer: 17. - Riddle: What number do you get if you multiply all the numbers on a phone keypad?
Answer: Zero. - Riddle: What is 25 divided by 1/5?
Answer: 125. - Riddle: I am a number between 30 and 40, divisible by 7. What number am I?
Answer: 35.
Logic-Based Math Riddles
- Riddle: There are 12 fish, and half of them drown. How many are left?
Answer: 12 (fish don’t drown!). - Riddle: If you multiply this number by any other number, the answer is always the same. What number is it?
Answer: Zero. - Riddle: If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?
Answer: 5 minutes. - Riddle: A bat and ball cost $1.10. The bat costs $1 more than the ball. How much is the ball?
Answer: 5 cents. - Riddle: A man is asked to write down two numbers. When multiplied together, the result is greater than when added together. What two numbers does he choose?
Answer: Any two positive numbers greater than 2. - Riddle: What two numbers, when multiplied, give the same result as when added?
Answer: 2 and 2. - Riddle: What is the smallest integer greater than zero that is both a perfect square and a perfect cube?
Answer: 64. - Riddle: I am three times as old as my son. In 10 years, I will be twice as old as him. How old am I?
Answer: 30. - Riddle: A farmer has 17 sheep. All but 9 die. How many are left?
Answer: 9. - Riddle: What 2-digit number is less than the sum of its digits multiplied by 5?
Answer: 14.
Algebra-Inspired Riddles
- Riddle: What’s the square root of me squared?
Answer: Me (anything squared and square-rooted equals itself). - Riddle: What comes before 1 and after 2, but equals both?
Answer: Zero. - Riddle: What two whole numbers, when multiplied, give a product less than their sum?
Answer: 1 and 2. - Riddle: I am a number that is the product of three prime numbers. If you add one to each of those numbers, their product equals me. What am I?
Answer: 30 (2 * 3 * 5 = 30). - Riddle: I am twice the sum of my digits. What number am I?
Answer: 18. - Riddle: Solve this equation: x² – 2x + 1 = 0. What’s x?
Answer: 1. - Riddle: If a number is divisible by both 3 and 5, it is divisible by what other number?
Answer: 15. - Riddle: What value of x satisfies the equation: 3x + 12 = 0?
Answer: -4. - Riddle: What is x in the equation x² = 49?
Answer: 7 or -7. - Riddle: What is x if x + 4 = 4 – x?
Answer: 0.
Time and Speed Riddles
- Riddle: A train leaves the station at 8:15 AM, traveling at 60 miles per hour. How far will it have traveled by 10:15 AM?
Answer: 120 miles. - Riddle: If you’re running a race and pass the person in second place, what place are you in?
Answer: Second place. - Riddle: If you travel 30 miles at 30 miles per hour, how long will it take?
Answer: 1 hour. - Riddle: What can travel faster than the speed of light but has no mass?
Answer: Information. - Riddle: How many times does the hour hand on a clock pass the minute hand in 24 hours?
Answer: 22 times. - Riddle: A car travels at 60 miles per hour for half of a trip and at 90 miles per hour for the other half. What’s the average speed?
Answer: 72 miles per hour. - Riddle: If you increase your speed by 50%, how much less time will it take to cover the same distance?
Answer: 33.3% less time. - Riddle: A man drives 90 miles in 3 hours. What is his average speed?
Answer: 30 miles per hour. - Riddle: Two trains are moving toward each other, each traveling at 60 miles per hour. How long will it take for them to meet if they’re 120 miles apart?
Answer: 1 hour. - Riddle: If you walk 2 miles to a store and run 2 miles back at twice the speed, how long does the entire trip take compared to walking the entire time?
Answer: 1.5 times as long.
More Math Riddles
- What has a face and two hands but no arms or legs?
- Answer: A clock.
- What is the smallest whole number that is both a square and a cube?
- Answer: 1.
- If two’s company and three’s a crowd, what are four and five?
- Answer: Nine.
- I am an odd number. Take away one letter, and I become even. What number am I?
- Answer: Seven.
- What is the sum of the angles in a triangle?
- Answer: 180 degrees.
- What number do you get when you multiply all the numbers on a telephone’s number pad?
- Answer: 0.
- If you add one to me, I become a million. What number am I?
- Answer: 999,999.
- What is the next number in the series 2, 4, 8, 16, 32, ?
- Answer: 64.
- How many sides does a hexagon have?
- Answer: 6.
- What is the product of all the numbers from 1 to 5?
- Answer: 120.
- If a dozen eggs cost 24 cents, how much do 100 eggs cost?
- Answer: 2 dollars.
- What is the smallest number that is divisible by all of the numbers from 1 to 10?
- Answer: 2520.
- What is the value of (2 + 3) × (4 + 5)?
- Answer: 45.
- What is the square root of 81?
- Answer: 9.
- What is the sum of the first 100 positive integers?
- Answer: 5050.
- How many months have 28 days?
- Answer: All of them.
- What is the result of 7 × 6?
- Answer: 42.
- If a book costs $3 and a pen costs $2, how much would 4 books and 3 pens cost?
- Answer: $18.
- What number is 6 less than 2 times 15?
- Answer: 24.
- How many degrees are in a right angle?
- Answer: 90.
- What is the value of 2^3?
- Answer: 8.
- What is the area of a square with a side length of 4 units?
- Answer: 16 square units.
- What is 20% of 150?
- Answer: 30.
- If you have 5 apples and you take away 2, how many do you have?
- Answer: 2.
- What is 15 divided by 3?
- Answer: 5.
- How many minutes are there in 2 hours?
- Answer: 120 minutes.
- If a triangle has two sides of length 5 and 7, what is the length of the third side if it’s an equilateral triangle?
- Answer: 5 or 7 (depends on the side lengths given).
- What is 7 squared?
- Answer: 49.
- How many edges does a cube have?
- Answer: 12.
- What is the value of 6 × (5 + 2)?
- Answer: 42.
- If a rectangle has a length of 8 and a width of 5, what is its area?
- Answer: 40 square units.
- What is the largest two-digit prime number?
- Answer: 97.
- If a pizza is cut into 8 slices and you eat 3 slices, how many slices are left?
- Answer: 5.
- What is the sum of 9 and 7?
- Answer: 16.
- What is the product of 9 and 9?
- Answer: 81.
- How many degrees are in a straight angle?
- Answer: 180.
- What is the difference between 15 and 9?
- Answer: 6.
- If a car travels 60 miles in 1 hour, how far does it travel in 4 hours?
- Answer: 240 miles.
- What is the square of 12?
- Answer: 144.
- If a triangle has angles of 30 and 60 degrees, what is the third angle?
- Answer: 90 degrees.
- What number comes next in the series 1, 4, 9, 16, 25?
- Answer: 36.
- How many sides does a pentagon have?
- Answer: 5.
- What is the value of 9 – 4 × 2?
- Answer: 1.
- If a clock shows 3:00, what is the angle between the hour and minute hands?
- Answer: 90 degrees.
- What is the sum of the first 10 even numbers?
- Answer: 110.
- How many minutes are there in a day?
- Answer: 1440 minutes.
- What is the value of 15% of 200?
- Answer: 30.
- What is the perimeter of a square with side length 6?
- Answer: 24 units.
- What is the next number in the sequence 2, 6, 12, 20, ?
- Answer: 30.
- How many faces does a tetrahedron have?
- Answer: 4.
- If a number is divisible by both 3 and 4, what is the smallest such number?
- Answer: 12.
- What is the value of (5 × 2) + (8 – 3)?
- Answer: 12.
- What is the cube root of 27?
- Answer: 3.
- How many edges does a rectangular prism have?
- Answer: 12.
- What is the area of a triangle with base 10 and height 5?
- Answer: 25 square units.
- What is 30 divided by 6?
- Answer: 5.
- If you subtract 5 from a number and then divide the result by 4, you get 3. What is the number?
- Answer: 17.
- What is the value of 3^4?
- Answer: 81.
- If a box contains 10 red balls, 5 blue balls, and 3 green balls, what fraction of the balls are green?
- Answer: 3/18 or 1/6.
- What is 10 + 2 × 5?
- Answer: 20.
- What is the sum of the first 5 prime numbers?
- Answer: 28.
- What is the smallest prime number?
- Answer: 2.
- What is the result of 8 × (3 – 1)?
- Answer: 16.
- How many degrees are there in a circle?
- Answer: 360.
- If a car travels 150 miles in 3 hours, what is its average speed?
- Answer: 50 miles per hour.
- What is the area of a rectangle with length 9 and width 7?
- Answer: 63 square units.
- How many days are there in a leap year?
- Answer: 366.
- What is the value of 11 – 4 + 6?
- Answer: 13.
- What is the square root of 121?
- Answer: 11.
- How many weeks are there in a year?
- Answer: 52.
- What is the value of 5^3?
- Answer: 125.
- If you have a dozen apples and give away 4, how many apples do you have left?
- Answer: 8.
- What is the value of 6 × (4 – 2)?
- Answer: 12.
- How many minutes are in 3 hours and 15 minutes?
- Answer: 195 minutes.
- What is the smallest even prime number?
- Answer: 2.
- If you double a number and then subtract 4, you get 8. What is the number?
- Answer: 6.
Conclusion
Now that you’ve tackled these 355 math riddles, your brain is sharper, your logic is stronger, and you’ve hopefully had some fun along the way.
Whether you’re a math enthusiast or just love a good puzzle, these riddles are perfect for testing your limits and improving your problem-solving skills. Share these with friends and keep the fun going!