What goes up but never comes down?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

What is more useful when it is broken?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

A man is shown a portrait painting. He looks closely, then tells, “Brothers and sisters have I none, but that man’s father is my father’s son!” Who is the man in the portrait?

Can you solve the below geography rebus by decoding the below rebus ?

How can you make number one disappear by adding something to it?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

If a wheel has 54 spokes, how many spaces are there between the spokes?

How can you take 2 from 5 and leave 4?