I’m tall when I’m young, and I’m short when I’m old. What am I?

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?

Can you identify the hidden rebus in the image below?

what does this below rebus represent identXQQQQQME

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?

What is next number in the pattern below:

131 517 192 123 ?

Using Only Five 5's and any mathematical operator make sum as 37

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

People put me on the table and cut me but do not eat me. What am I?