数学求解

隐若水上

og12Diagnostic tese Quantitbtive Sample 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 surveyed required neither
computer skills nor writing skills?
(1)  Of those companies surveyed that required
computer skills, half required writing skills.
(2)  45 percent of the companies surveyed require
writing skills but not computer skills.
第一条看不到明白，求解释

线香花火

需要computer skill 的有一半需要writing skill...?