How can a man go eight days without sleep?

Why is the Hole below a Lock?

How is a fly different from a mosquito?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

Who is that with a neck and no head, two arms and no hands? What is it?

John is the son of Jacob.
So,
Jacob is the_____of John's father?

Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?