OG里Diagnostic Test里的一题

eddycheng

A marketing firm detemined that, of 200 households surveyed, 80 used neither Brand A or Brand B soap, 60 used only Brand A soap, and for every household that used both brands of soap, 3 used only Brand B sopa. How many of the 200 households surveyed used both brands of soap?

(a) 15

(b) 20

(c) 30

(d) 40

(e) 50

其实，这个题目不是语法题，但看他的解释的时候，书上说“3 used”,是3倍的意思。这个是为什么呢？

谢谢各位啊。

xuyidan1210

for every...3 used...就是说如果用两种香皂的人数是1份，那么用B的是3份.

[此贴子已经被作者于2008-6-19 22:15:58编辑过]

alexws

'for every household that used both brands of soap, 3 used only Brand B sopa'

if there is1 household uses both brands,  there will be 3 households only use brand B.

eddycheng

是这个意思啊.谢谢xuyidan1210和alexws.....