Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

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

It belongs to you, but other people use it more than you do. What is it?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

Suppose you are a girl candidate and sitting in an interview. Suddenly the interviewer asks you, 'What if one morning you wake up and find out that you are pregnant?

How will you reply to such a question?

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

How many sides does a circle have?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

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