Bill is a good student and an intelligent boy. He likes to study arithmetic, and he can do all of the arithmetic problems in his book easily. One day on his way to school Bill passed a fruit store. There was a sign in the window which said, "Apple-Six for five cents." An idea came to Bill and he went into the store. "How much are the apples?" he asked the store. "Six for five cents." "But I don't want six apples." "How many apples do you want?" "It is not a question of how many apples I want. It is a problem in arithmetic." "What do you mean by a problem in arithmetic?" asked the man. "Well, if six apples are wroth five cents, then five apples are worth four cents, four apples are worth three cents, three apples are worth rwo cents, two apples are worth one cent and one apple is worth nothing. I only want one apple, and if one apple is worth nothing then it is not necessary for me to pay you." Bill picked out a good apple, began to eat it, and walked happily out of the store. The man looked at the young boy with such surprise that he could not say a word.