Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

Prove that twice of ten is the same as twice of eleven.

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

why number 8549176320 is one of a kind?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

Two old friends, Jack and Bill, meet after a long time.

Three kids
Jack: Hey, how are you, man?
Bill: Not bad, got married and I have three kids now.
Jack: That's awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool..But I still don't know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh, now I get it.

How old are Bill's kids?

How can you make a TV, a bed, a dog, and a car liquid?

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?