What is the coolest letter in the alphabet?

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

Which point will the car reach to go out?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

What is red and smells like blue paint?

As shown in the picture below, we can see a boy hanging on the tree branch to save his life. There are various ways in which he can die like1. A snake hanging toward the right waiting to bite the boy.2. A roaring Lion near the tree.3. Two crocodiles are ready to attack if the boy reaches near water. The tree is chopped to some extent, so can fall as if he moves a lot. Can you give this boy an escape plan?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

What goes through cities and fields, but never moves?