GWD10-Q11

[凱薩琳]

In a corporation, 50 percent of the male employees and 40 percent of the female employees are at least 35 years old. If 42 percent of all the employees are at least 35 years old , what fraction of the employees in the corporation are females?

A.3/5
B.2/3
C.3/4
D.4/5
E.5/6

Ans:D

[StanleyHuang]

假設男的 m 人，女的 f 人
(0.5m+0.4f)/(m+f) = 0.42 ==> f=4m
所求 = f/(f+m) = 4m/5m = 4/5

[凱薩琳]

感謝回答...