GRE®
返回
Question 3 Selected one answer choice
收藏
笔记
反馈
我的笔记
5000
保存
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Susan travels by car at an average speed of 50 miles per hour for 4 hours and then at an average speed of 20 miles per hour for 2 hours. What is her average speed, in miles per hour, for the entire 6-hour trip?

A.25

B.30

C.35

D.40

E.45

我的答案：