Mr Hill goes to a shop. He wants to buy some food for supper. He sees a woman with ten children. They are wearing the same clothes—white hats, blue jackets and black trousers.
"Are all the children yours?" Mr Hill asks the woman.
"Yes, "she answers.
"Do you always put the same clothes on them?"
"Yes, "answers the woman. "We don't want to lose any of them. When they are with other children, it's easy to find them out. Their clothes are different. "