History
Old man Bob wanted to leave all of his money to one of his three sons, but he didn't know which one he should give it to. He gave each of them a few coins and told them to buy something that would be able to fill their living room. The first man bought as much straw as he could, but there was not enough to fill the room. The second bought some dirt, but he still did not fill the room. The third man bought two things that filled the room when used together, and obtained his father's fortune. What were the two things that the man bought?
