What is at the end of a rainbow?

What goes up but never comes down?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

What two things can you never eat for breakfast?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

The more it dries, the wetter it becomes. Can you tell what it is?

What English word has three consecutive double letters?