Number Logic Riddles
I am an odd number. Take away one letter and I become even. What number am I?
Show AnswerHide Answer
Seven.
Using only addition, add eight 8s to get 1,000. What is one solution?
Show AnswerHide Answer
888 + 88 + 8 + 8 + 8.
A bat and a ball cost $1.10. The bat costs $1 more than the ball. How much is the ball?
Show AnswerHide Answer
Five cents.
If 5 machines make 5 gadgets in 5 minutes, how long do 100 machines need for 100 gadgets?
Show AnswerHide Answer
Five minutes.
What three numbers give the same result whether added or multiplied?
Show AnswerHide Answer
1, 2, and 3.
My tens digit is five more than my ones digit. My hundreds digit is eight less than my tens digit. What number am I?
Show AnswerHide Answer
194.
A farmer has 17 sheep and all but 9 run away. How many are left?
Show AnswerHide Answer
Nine.
Divide 30 by one half and add 10. What do you get?
Show AnswerHide Answer
70.
How can you make seven even without addition, subtraction, multiplication, or division?
Show AnswerHide Answer
Remove the letter S from the word SEVEN, leaving EVEN.
What weighs more: a pound of feathers or a pound of bricks?
Show AnswerHide Answer
Neither. Both weigh one pound.
Tricky Adult Math
How can you add eight 4s together so the total equals 500?
Show AnswerHide Answer
444 + 44 + 4 + 4 + 4.
Two ducks are in front of a duck, two behind a duck, and one in the middle. How many ducks?
Show AnswerHide Answer
Three ducks.
In a race, you pass the runner in second place. What place are you in?
Show AnswerHide Answer
Second place.
A number doubled is 20 more than itself. What is the number?
Show AnswerHide Answer
20.
How many times can you subtract 5 from 25?
Show AnswerHide Answer
Once.
A clock loses 5 minutes every hour. After 6 hours, how far behind is it?
Show AnswerHide Answer
30 minutes.
A brick weighs one pound plus half a brick. How much does a brick weigh?
Show AnswerHide Answer
Two pounds.
A price rises 50 percent, then falls 50 percent. What happens overall?
Show AnswerHide Answer
It falls by 25 percent.
Using four 9s and any operations, how can you make 100?
Show AnswerHide Answer
99 + 9/9.
If three workers build three tables in three hours, how many tables can six workers build in six hours?
Show AnswerHide Answer
Twelve tables.
Puzzle Night Extras
A square has area 64. What is its perimeter?
Show AnswerHide Answer
32.
What comes next: 1, 1, 2, 3, 5, 8?
Show AnswerHide Answer
13.
I am a two-digit number. My digits add to 9 and reverse to make 27 more. What am I?
Show AnswerHide Answer
36.
If x plus x plus x equals 42, what is x?
Show AnswerHide Answer
14.
A dozen eggs cost $3. How much do eight eggs cost at the same rate?
Show AnswerHide Answer
Two dollars.
What is 10 percent of 10 percent of 1,000?
Show AnswerHide Answer
10.
What shape has infinite lines of symmetry?
Show AnswerHide Answer
A circle.
I am the total when all angles in a triangle gather. What am I?
Show AnswerHide Answer
180 degrees.
I am the number that is both a square and a cube under 100. What am I?
Show AnswerHide Answer
64.
What is the smallest number that is divisible by 1, 2, 3, 4, 5, and 6?
Show AnswerHide Answer
60.
FAQ
Are answers included?
Yes. Every riddle includes the answer.
How hard are these?
They mix classic adult brain teasers with number logic.
Want tougher math?
See hard math riddles for adults.