A hiker walking at a constant rate of 4 miles per hour is passed by a cyclist traveling in the same direction along the same path at a constant rate of 20 miles per hour. The cyclist stops to wait for the hiker 5 minutes after passing her, while the hiker continues to walk at her constant rate. How many minutes must the cyclist wait until the hiker catches up?
(A)
(B) 15
(C) 20
(D) 25
(E)
答案是C
这道题目我完完全全没有看懂。。。。作者: yoyo561116 时间: 2010-4-8 08:08
the cyclist is 16mile/hour faster than the hiker, so after 5 mins the cyclist is 16*1/12 miles ahead of the hiker. If the cyclist stops then, it will take the hiker 4/3/4=1/3hour to catch up, which is 20 mins. The answer should be (C).作者: 花儿笑 时间: 2010-4-8 09:54
