GWD 1-37

hedgeforfun

Q37. Of the 500 business people surveyed, 78 percent said that
they use their laptop computers at home, 65 percent said they use them
in hotels, and 52 percent said that they use both at home and in
hotels. How many of the business people surveyed said that they do not use their laptop computers either at home or in hotels.

A.45
B.55
C.65
D. 95
E.130

How come my answer is bigger than any of the above? 各位可不可给我详细解释一下呢？我的数学底子不好。谢了。

fdgggd

这种题目画一个表格很好解的。A+B=78,A+D=65, A=52, ==>B=26, D=13,

C+D+A+B=100=>C+D=22==>C=9, 所以答案为500*0.09=45.

At home & at hotel- A

Not at home, but at hotel-D

At home, not at hotel- B

Not at home or not at hotel--C