At dinner time, Nasreddin finds no meat on the table. He asks his wife, "What happened to the meat?"
His wife replies, "The cat ate it."
Nasreddin breezes into the kitchen, puts the cat on the scales, and discovers the cat to be weighing three pounds. Nasreddin quizzically questions the result, "If the meat I brought home weighed three pounds, then, where is the cat? And, if this happens to be the cat, then what happened to the meat?"