GWD 29-5

According to a survey, 93 percent of
teenagers have used a computer to play games, 89 percent have used a computer
to write reports, and 5 percent have not used a computer for either of these
purposes.  What percent of the teenagers
in the survey have used a computer both to play games and to write reports?

A.    82%

B.     87%

C.     89%

D.    92%

E.     95%

如果没猜错的话你应该是Alex..

答案是B   93+89-（1-5）=87

恩  是很简便