Three travelling salesman share a hotel room for $30. After checking in, the manager tells the bellhop - "I forgot the room was on special for $25. Here's $5 to give them back." In the elevator, the bellhop doesn't know how to split $5 three ways, so he pockets $2, and gives each salesman $1. So each salesman paid $9. Three times nine is $27. Plus $2 in the bellhop's pocket is $29. Where's the other $1 ?

Something simple,
What colour is Yaks milk?

When a woman says No while undressing.

the first koan of buddism. what is the sound of one hand clapping?

A farmer planted five straight rows of trees with four trees in each row for a total of ten trees.

How?

Silly.

Why do farts stink?

So deaf people can enjoy them, too.

One of my favourites goes something along the lines of.

"One day, the younger of a pair of twins celebrated their birthday. Two days later, the elder twin celebrated theirs. How?"

In the movie Labyrinth
The girl faces two doors guarded by two guards. One door is certain death the other her path forward. One guard always tells the truth one guard always lies. She can have one question.

My favorite riddles has always been the contest between Bilbo Baggins and Gallum...

One of the coins isn't a dime..clever!

This riddle came from the MENSA book we used to play with as kids.

You are traveling through a country of people who are either green or red. All the green people must tell the truth, and all the red people always lie. You reach an intersection at dusk and want to know which way to turn to reach the nearest town. There is a man standing nearby, but it's almost dark and you can't tell what color he is.

What one question could you ask to get correct directions that wouldn't matter which color the man was?

Who dat, say who dat, when I say who dat?