If two's company, and three's a crowd, then whats four and five ?

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

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?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

If 1+9+8=1, what is 2+8+9?

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

what does the below math rebus puzzle mean?

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?