Basic Numbers (Easy)
Find the Patterns (Easy-Medium)
Guess the Word (Easy-Medium)
Math Riddles (Easy-Medium)
Challenges for old people (Hard)
100
What is 5 + 7?
5 + 7 = 12
100
2, 4, 6, __
2, 4, 6, 8
100
The answer to an addition problem
Sum
100
If you eat 2 out of 5 apples, how many are left?
3 apples are left.
100
A hotel with infinitely many full rooms gets 1 new guest. How does the hotel accommodate them?
Move the person in room n to room n+1.
200
What number comes after 999?
1000 comes after 999.
200
100, 90, 80, __
100, 90, 80, 70
200
The longest side of a right triangle
Hypotenuse
200
A week has 7 days. How many days do two weeks have?
14 days
200
A hotel with infinitely many full rooms gets infinite new guests. How does the hotel accommodate them?
Move the person in room n to room 2n.
300
What is half of 18?
One half of 18 is 9.
300
2, 4, 8, 16, __
2, 4, 8, 16, 32
300
A number that can only be divided by 1 and itself
Prime number
300
How many legs does two people and four dogs have in total?
20
300
How many squares are there in a chessboard?
Hint: it's not 64
204
400
What is 4 x 9?
4 x 9 = 36
400
1, 4, 9, 16, __
1, 4, 9, 16, 25
400
The distance around a circle
Circumference
400
Which is heavier: 1kg of feathers or 1kg of rocks?
They're all 1kg, so they have the same weight.
400
You are trapped in a room with two doors. One door leads to freedom. The other leads to doom.
There are two guards: one always tells the truth, one always lies.
You may ask one question to one guard. What do you ask to guarantee you choose the correct door?
Ask: “Which door would the other guard say leads to freedom?”
Then, choose the opposite door.
500
I am even, between 14 and 20, and divisible by 3. What am I?
18
500
1, 1, 2, 3, 5, 8, 13, __
1, 1, 2, 3, 5, 8, 13, 21
(Fibonacci Sequence, the sum of the previous two terms)
500
A line that touches a circle at exactly one point
Tangent
500
If two cats take one minute to catch two mice, then how much time does one cat take to catch two mice?
2 minutes
500
The 9 Dots Puzzle - Connect the dots using four straight lines without lifting your pencil.
