“Daddy, can I learn to play the violin?” young Sarah asked her father. She was always asking for things and her father was not very pleased.
“You cost me a lot of money, Sarah,” he said, “First you wanted to learn horse riding, then dancing, and then swimming. Now it's the violin.”
“I'll play every day, Daddy,” Sarah said, “I'll try very hard.”
“All right,” her father said, “This is what I'll do. I'll pay for you to have lessons for six weeks. At the end of six weeks you must play something for me. If you play well, you can have more lessons. If you play badly, I will stop the lessons.”
“Ok, Daddy,” Sarah said, “That is fair.”
He soon found a good violin teacher and Sarah began her lessons. The teacher was very expensive, but her father kept his promise.
The six weeks passed quickly. The time came for Sarah to play for her father.
She went to the living room and said: “I'm ready to play for you, Daddy.”
“Fine, Sarah,” her father said, “Get started.”
She began to play. She played very badly. She made a terrible noise. Her father had one of his friends with him, and the friend put his hands over his ears.
When Sarah finished, her father said, “Well done, Sarah. You can have more lessons.”
Sarah ran happily out of the room. Her father's friend turned to him. “You have spent a lot of money, but she still plays very badly.” He said. “Well, that's true,” her father said. “But since she started learning the violin I have been able to buy five apartments in this building very cheaply. In another six weeks I'll own the whole building!”
“爸爸， 我能学拉小提琴吗？”小莎拉问爸爸。她总是要东要西的，爸爸不太高兴。
“我都为你花了那么多钱了，莎拉。”他说，“你先是要学骑马，后来又要学跳舞，之后又想学游泳。现在又换小提琴了。”
“我会天天拉琴的，爸爸。”莎拉说，“我会刻苦练习的。”
“好吧，”爸爸说，“那这样吧。我先给你交够六周的学费，第六周结束的时候，你必须给我拉几首曲子。拉得好的话，我就让你继续学。拉不好的话，你就别学了。”
“行，爸爸，”莎拉说，“这办法很公平。”
爸爸很快找了一位优秀的小提琴老师，莎拉开始学琴了。老师收费很贵，可爸爸还是遵守了自己的承诺。
六周很快过去，到了莎拉给爸爸拉琴的时候了。
她走进客厅，说：“爸爸，我准备好给你演奏了。”
“好的，莎拉。”爸爸说，“开始吧。”
莎拉拉起琴来，拉得很糟，简直是噪声。爸爸的一个朋友当时也在场，那位朋友还用手捂住了自己的耳朵。
演奏完毕，莎拉的爸爸说：“拉得好，莎拉。你可以继续学琴。”
莎拉高兴地跑出房间。那位朋友发问了：“你花了那么多钱，她居然还是拉得这么糟。”“是啊，你说得对。”莎拉爸爸说，“可是自从她开始学琴，我已经低价在这栋楼里买下五套公寓了。再过六周，整栋楼就都是我的了！”
利弊向来是相倚相伏的。