It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

What goes up but never comes down?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

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

If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?

No matter how little or how much you use me, you change me every month. What am I?

In the given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

Replace all '*' with digits 1, 2, 3, 4, 5 and 6 to make below statement true.

* *
x *
=====
* * *

Consider all the numbers between 1 and 1 million. Among all these numbers, there is something very special about the number 8 and the number 2202. What is it?

A man dies of old age on his 25 birthday. How is this possible?