A report from a 9th grader：
Our school campus has twenty buildings spread over seventy acres. There were two soda machines. Recently they added a third. I overheard the workers arguing where to put the new machine. They decided to put it next to the other machine because that way people would notice it when buying drinks. There was one tiny flaw in that plan. The two machines sold the same drinks， and the new one cost an extra 75 cents.