What is the coolest letter in the alphabet?

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

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

How is the moon similar to a dollar?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

There is something which you can be arrested for attempting but not for successfully completing.

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

What brings you down but never up?

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?