Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.

Why do people go to bed?

What number should come in place of the question mark below?

John was piloting a plane behind a car but was never able to overtake it. Why?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

What is red and smells like blue paint?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

What can jump higher than a building?