What has hands, but can’t clap?

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?

During which month do people sleep the least?

What does this rebus riddle means ?

I have branches, but no fruit, trunk or leaves. What am I?

Which number should replace the question mark?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

Today, I celebrated my 32nd birthday but I was born in 1972.
How is this possible?

Count the number of triangles in the below picture?

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?