※ 引述《KMI (无奈)》之铭言： : DS: 刚刚模考做到 : A certain one-day seminar consisted of a morning session and an afternoon : session. If each of the 128 people attending the seminar attended at least : one of the two sessions, : how many of the people attended the morning session only? : 1) 3/4 of the people attended both sessions. : 2) 7/8 of the people attended the afternoon session. : 答案: B 假设参加早场的人为A 午场的人为B 则128人指的是 A+B (AＵB) 1. 为　AｎB (交集) 只能推得参加的总人数 A+B-(AｎB)=参加总人数 2. 7/8参加午场 所以1/8参加早场 128* (1/8) = 16 答案为B : A certain city with a population of 132,000 is to be divided into 11 voting : district, and no district is to have a population that is more than 10% : greater than the population of any other district. What is the minimum : possible population that the least populated district could have? : 1. 10700 : 2. 10800 : 3. 10900 : 4. 11000 : 5. 11100 : 答案: D 题目指出 没有任合一个地区会超出另一个地区 10%人口 假设一地区最少人口为a 别的地区那最多人口就是 a* 110% = 1.1a a有最小值的情况---> 其他所有10个地区都是刚好超出a有10%的人口数 所以 (1.1a+1.1a+.....1.1a)+a = (1.1a)*10 + a = 132000 解得a为11000人 恩~ 我是这样想的 囧> --

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