You measure my life in hours
I serve you by expiring
I vanish faster when I am thin
and slower when I am thick
The wind is my energy
What am I?

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

Which number comes next in the number series?

2, 9, 30, 93, ?

Can you find out who is the kidnapper in below Picture and why, Explain ?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Through your logical capabilities, can you make 7 an even?

Can you write down eight eights so that they add up to one thousand?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?