JJ recent 题目 -math

题目大概是
                The average number of days per project for a series of 12 projects is N. A series of projects which need 24 days to complete is going to be done with another way that it takes n-3/4 days per project to complete the projects. How many days it will take to complete the projects if it is done by the new way?

A)    12 (不确定)

B)     16 (不确定)

C)    18

D)    32

E)     33

How to slove it? thanks

enviro你好啊～剛剛在其他帖子上看到你找的GWD原題～甚是感謝！

這題我以為題目上似乎有點怪怪的，我這樣分析：

一個package中有12個計畫,平均完成時間為N天.所以完成所有計畫需要12N天.

第二句話說如果計畫原本需要24天完成,現在改以新方法做，平均一個計畫省

0.75天,所以關鍵是如果知道計畫數,就可以算出答案,因此，如果題目的意思是12個計畫

需時24天,則答案應為15天.