【求助】12版OG，诊断测试，25页第34题-DS

jacjoaquin

求助：12TH OG-DIAGNOSTIC TEST-P25-NO.34-DS
12版OG，诊断测试，25页第34题。
34. Of the companies surveyed about the skills they required in prospective employees, 20 percent required both computer skills and writing skills. What percent of the companies surveryed requried neither computer skills nor woring skills?
(1) Of those companies surveyed that required computer skills, half required writing skills.
(2) 45 percent of the companies surveyed required writing skills but not computer skills.

我看了OG 的解答，看了好几遍还是没有弄明白：
(1) Of those companies surveyed that required computer skills, half required writing skills.
这句的意思是：“要求员工掌握电脑技能的公司里，有一半要求写作技能。”吗？
如果是的，为什么解答中说要求电脑技能和写作技能的人数一样，都是20%呢？
看不懂啊……求解答！！大菜鸟谢谢各位了……

jacjoaquin

谢谢大侠们！！！！！！！！！！！！

xiaomimi

(1) alone can only tell the 20% of total employees who are both C and W is half of the C(only C and C+W). This is only 40%, could not tell the other 60%
(2) alone neither can tell
But is (1) and (2), 20%(only C) + 20%(both C and W) +45%(only W) =85%<100%
so , neither C nor W will be 1-85%=15%.
The key to answer this Q is convert the half to be 0.5 then with the 20% of total to deduce the 40%.
Hope it helps. 如果有问题， 请继续问。我都在努力。一起加油

moeileen

题的意思是：
在公司测试有潜力的员工中，20%的人同时具备电脑技能和写作技能：写作电脑=20%总和。同时不具备两种技能的人占比多少？
1.在要求的具备电脑技能的人中，一半具有写作技能：写作=电脑*1/2
2.45%的人要求有写作技能而无电脑技能：只写作=45%总和

对1. 求不写作不电脑的百分比，已知写作电脑=20%总和

只写作+只电脑+写作电脑+不写作不电脑=总和 变为 只写作+只电脑+不写作不电脑=80%总和
只写作+写作电脑=1/2只电脑+1/2写作电脑 变为 只写作-1/2只电脑=-1/2写作电脑=-10%总和

求不出

对2. 只写作=45%总和
只写作+只电脑+不写作不电脑=80%总和

求不出

对1.与2. 即可