看一道JJ题

RichardLau

44.(PS) there are two groups, part-time and full-time, part-time is 1/3 of the total, and part-time worked 3/5 hours of full time, ask what fractions of part-time working hours in total hours? 

我怎么没看懂 题目什么意思？

这是给出的答案：设总时间a, hours of full time为b 则有[(a/3)*(3b/5)]/[(a/3)*(3b/5)+2ab/3]

a/3是人数，3b/5是工作时间，这两个相乘是什么道理呢？

谢谢

RichardLau

 fractions of part-time working hours in total hours不就是3/5么？

wowowoccc

是[1*(3/5)]/[1*(3/5)+2*1]=3/13

戴安娜

 假设part-time group有一个人,则full time group有两个人, part-time group的人worked 3 小时 则full time group的人works 5小时,所以总共工作时间是3+2*5=13小时,这样,part-time group的人working hours in total hours就是3/13.

[此贴子已经被作者于2009-3-7 8:00:33编辑过]

RichardLau

明白了，多谢了哈，

wangxiaoqing

try real numbers
the question is not hard