New Car

[Passing Time]

Father hears banging from the basement and wanders downstairs to what's happening. He finds his son Timmy pounding a nail into the wall. "Why are you banging that nail?" asks the father. Timmy replies, "it's not a nail, it's a worm. I mixed some chemicals from my chemistry set, put it on the worm and it became hard as a rock". "Tell you what son", says the father, "give me your formula and I'll buy you a new Volkswagen"

Timmy agrees and next day he and his dad go into the garage to look at the new car. However, all Timmy can see is a brand new Mercedes. "Where's my Volkswagon" asks Timmy, "Behind the Mercedes" says father. "By the way, the Merc's from your mother"