[問題]新pp問題6

[mht]

6. How many hours did it taken Helento drive from her house to her parents' house?
(1)Helen's average speed on this trip was 72 kilometers per hour.
(2)If Helen average speed on this trip had been 8 kilometers per hour greater, it would have taken her 1 hour less.
<這個句子不大懂它的意思>
Ans. C

[doggyface922]

(2)If Helen average speed on this trip had been 8 kilometers per hour greater, it would have taken her 1 hour less.
這是說，如果Helen "新時速" 比"之前的時速" 大 8 kilometers per hour ，則時間會減少一個小時。

條件一二單獨看都不充分
ㄧ起看，設距離為X

則 X/72 = X/80 +1 => X=720 => 時間 720/72=10 hr