※ 引述《KMI (無奈)》之銘言： : DS: 剛剛模考做到 : 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 假設參加早場的人為A 午場的人為B 則128人指的是 A+B (AＵB) 1. 為　AｎB (交集) 只能推得參加的總人數 A+B-(AｎB)=參加總人數 2. 7/8參加午場 所以1/8參加早場 128* (1/8) = 16 答案為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 題目指出 沒有任合一個地區會超出另一個地區 10%人口 假設一地區最少人口為a 別的地區那最多人口就是 a* 110% = 1.1a a有最小值的情況---> 其他所有10個地區都是剛好超出a有10%的人口數 所以 (1.1a+1.1a+.....1.1a)+a = (1.1a)*10 + a = 132000 解得a為11000人 恩~ 我是這樣想的 囧> --

※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 61.216.196.118 ※ 編輯: jjhgfr 來自: 61.216.196.118 (09/27 11:16)