My daughter Laura and her classmates were baking a cake in cooking class one day. After about 35 minutes the teacher said, “Laura, would you check on the cake? Just put a knife in it, and if it comes out clean the cake is ready.”
After about 10 minutes Laura came back. “What took you so long?” the teacher asked.
“Well,” said Laura, “I stuck the knife in the cake and it came out so clean that I stuck all the other dirty knives in too.”