作者piapiapia (piapiapia)
看板GMAT
标题[计量] PP DS 46
时间Thu Aug 7 16:48:42 2008
46. 3960-!-item-!-187;#058&003582
How many hours did it take Helen to drive from her house to her parents' house?
(1) Helen's average speed on this trip was 72 kilometers per hour.
(2) If Helen's average speed on this trip had been 8 kilometers per hour greater, it would have taken her 1 hour less.
答案是 C
1) D/72
2) D/S = D/(S+8) -1
1)+2) 算出答案是负的
我的问题是:既然算出来答案是负的
这样还能选C嘛? 这样不太合逻辑。
谢谢!
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※ 编辑: piapiapia 来自: 118.167.201.56 (08/07 16:54)
1F：推 flac:第二个式子列错了 应该是+1 不是-1 08/07 17:01
2F：→ flac:答案是10小时 08/07 17:03
3F：→ piapiapia:我粗心了 感谢!! 08/07 17:07