What building has the most stories?

What is greater than gold but cannot be bought. it can never be sold and can earn if its sought. though it can be broken, it can still be fixed. for by birth it can't start nor by death it is ended.what am i?

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

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

There are 3 apples in the basket and you take away 2. How many apples do you have now?

What always comes into a house through the keyhole?

You are on a Boat in the mid of a river. You have two cigarettes with you. One of these two you have to light, how will you light the cigarette?

You bought me for dinner but never eat me. What am I?

Which alphabet letter is a question?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?