※ 引述《ivanos (Peel quickly and see)》之铭言： : 朋友写信问我一个轻松有趣的题目，跟大家分享一下 : Mr. Short, his sister, his son, and his daughter are fond of golf and often : play together. The following statements are true of their foursome: : (1) The best player's twin and the worst player are of the opposite sex. : (2) The best player and the worst player are the same age. : Which one of the foursome is the best player? 由条件一知道，有一组人是双胞胎 先以年龄分类，Short, his sister一组，the son and the daughter一组推想 会发现没有任何人同时满足两个条件 (双胞胎是父亲和姑姑，则不可能有任一人和子女同年；反之亦然) 所以双胞胎一定是子女，然後Short's sister的年龄和Short的子女相同 才会出现又有双胞胎又有第三人与他们同龄的状况 此时根据条件一知道，best player在双胞胎里面， 所以根据条件二知道，worst player可先确定为姑姑 这时从条件一得知，姑姑和儿子性别相反， 所以best player是女儿。 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 61.231.10.221