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?
答案是20
何解啊？？？
-- by 会员 believezx (2010/10/13 18:44:08)
这道题的意思是说cyclist在经过hiker5分钟之后决定等一下hiker，那么需要等几分钟hiker才能追上他呢？
5分钟的时候两个人相差了（20-4）*5min/60hr 英里
用上面的miles除以hiker的速度4miles/hour，可以得到答案为20
-- by 会员 cherishzhao (2010/10/13 19:06:13)
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?
答案是20
何解啊？？？
-- by 会员 believezx (2010/10/13 18:44:08)
楼主这道题问的好，我感觉这是语言陷阱的一个典型形式。我感觉其实问题可能出在这句话The cyclist stops to wait for the hiker 5 minutes after passing her。我一开始也以为是，骑自行车的人在超过走路的人后停下来等他5分钟，这样这道题就没法做了。我自己分析了这句话，才明白意思是，这个骑自行车的人在超过走路人后的5分钟后停下来等他。这样就对了。
做法我想楼主一定能解出来。嘿嘿！
-- by 会员 超人归来 (2010/10/13 19:06:56)
