If 21x = 79x, what is the value of x?

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

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

What is the coolest letter in the alphabet?

When I asked a girl's name she told me her name is the date '07/09/2001'.

I thought for a few seconds and then I got her name. Do you?

The centre of the third figure is empty. What digit should fit inside?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?