There is a bartender who wants to make an impossible challenge to get more money. So he makes a challenge and three men want to enter.
They ask what they have to do to enter.
The bartender tells them, "You each have to put an 100 dollar bill in the tip jar, and whoever wins gets all the money inside of the tip jar.

All the men put one one hundred dollar bill in the jar each. They ask whats the challenge.

The bartender tells them, "You have to start off with fifteen shots."

The first man fails immensely.

The second man fail miserably.

But the third is still going strong. So he asks what he has to do next.

"You have to get the gold tooth from the the dog in the back, and then screw the 87 year old hooker upstairs."

So the man goes to the back and there is a lot of ruckus, yelping, and banging, and the man comes back and asks, "Alright. Now where's the hooker with the gold tooth?"