GWD-6-14,请帮我看看为什么选E？

baby11

Q14:

If the average (arithmetic mean) of x, y, and 20 is 10 greater than the average of x, y, 20, and 30, what is the average of x and y?

A. 40

B. 45

C. 60

D. 75

E. 95

Answer: E

我计算出来的结果是-25，但如果题目中Greater than改为less than答案就正确啦

sammen

(x+y+20)/3=(x+y+20+30)/4+10

baby11

以下是引用sammen在2005-1-3 21:21:00的发言： (x+y+20)/3=(x+y+20+30)/4+10

呵呵，谢谢