Funny joke

A man decides to have a face-lift for his birthday. He spends $5,000 and feels really good about the results. On his way home, he stops at a newsstand and buys a paper. Before leaving, he says to the sales clerk, "I hope you don't mind me asking, but how old do you think I am?"
"About 35," was the reply. "I'm actually 47," the man says, feeling really happy. After that, he goes into McDonalds for lunch and asks the clerk the same question. The reply is, "Oh, you look about 29"."I am actually 47." Later, while standing at a bus stop, he asks an old woman the same question.
She replies, "I am 85 years old, and my eyesight is going. But when I was young, there was a sure way of telling a man's age. If I put my hand down your pants and play with your balls for 10 minutes, I will be able to tell you your exact age." As there was no one around, the man thinks, What the hell and lets her slip her hand down his pants. Ten minutes later, the old lady says, "Okay, it's done. You are 47." Stunned, the man says, "That was brilliant. How did you do that?" The old lady replies, "I was behind you at McDonalds."