What number comes next in the series?

5 15 5 18 5 24 14 20 _

Can you start the fire using two pieces of wood?

Take one out and scratch my head, I am now black but once was red. What am I?

Here is what you have to do. You have to throw a ball as hard as you can but it must return back to you even if it does not bounce at anything. Also, you have nothing attached to the ball. There is no one on the other end to catch that ball and throw it back at you.

How will you do it?

It belongs to you, but other people use it more than you do. What is it?

Wednesday, Steve and Pam go to a restaurant to eat lunch. After eating lunch, they pay the bill. But Steve and Pam do not pay the bill. So…who does?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Our product and our sum always give the same answer. Who are we?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

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?