GWD 22-02

[livory]

Q2:
In planning for a trip, Joan estimated both the distance of the trip, in miles, and her average speed, in miles per hour. She accurately divided her estimated distance by her estimated average speed to obtain an estimate for the time, in hours, that the trip would take. Was her estimate within 0.5 hour of the actual time that the trip took?
(1)Joan’s estimate for the distance was within 5 miles of the actual distance.
(2) Joan’s estimate for her average speed was within 10 miles per hour of her actual average speed.

Answer: E


不是1+2即可算出嘛?

不知道哪裡不對耶!請高手指點一下!謝啦!

[amazingslim]

應該要最大的距離/最小的速率=最大的時間(within)
if d=5 miles, s=1mile per hour
t=5

if d=1 miles, s=10mile per hour
t=0.1

[davidpcwang]

太奸詐了, 問題竟然出在"average"