A Logical Misunderstanding
Rivkah asks Shlomo, "I'm short of some ingredients for the cake I'm baking, so could you please get some things for me from the supermarket?"
"Of course I can, darling," replies Shlomo. "What do you need?"
"Please get one carton of milk, and if they have eggs, get six." replies Rivkah.
Fifteen minutes later, Shlomo returns with six cartons of milk. Rivkah is furious with him. "You shmo! Why on earth did you buy six cartons of milk?"
"Because they had eggs," he replies.