※ 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 画圈圈图会比较好理解 学生有三种(M: morning session; A:Afternoon session) I. M but not A II. both M & A III. A but not M 1)只知道M & A交集的人数 --> not sufficient 2)知道I+II=7/8*128=112,又题目给说所有的学生=I+II+III 所以可以得知attend the M only的人数有128-112=7人 ---> sufficient! Therefore, choose the answer 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 题目重点"任何一个district的人均不大於另一个district人数的10%" --->即最多和最少人数的district差10% 设这11个district中人数最小者有x人 最极端的情形...就是另外10个district人数均是1.1x 则1.1x*10+x = 132000 求解得出x=11000 Choose answer D --

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