In a train compartment, there are 3 men and a ravishing young girl. The four passengers join in conversation, which very soon turns to the erotic. 

Then, the young girl proposes, "If each of you will give me $1.00, I will show you my legs."

The men, charmed by this young girl, all pull a buck out of their wallet. And then the girl pulls up her dress a bit to show her legs. 

Then she says, "If each of you gentlemen will give me $10.00, I'll show you my thighs,".

And men being what they are, they all pull out a ten dollar bill. The girl pulls up her dress all the way to her legs in full. 

Conversation continues, and the men, a bit excited, have all taken off their coats. 

Then the young girl says, "If you will give me $100, I will show you where I was operated for appendicitis." All three fork over the money. 

The girl then turned to the window and points outside at a building they're passing. "See there in the distance. That's the hospital where I had it done!"