针对一些常考的
SAT数学解题方法中关于逻辑推理的部分是SAT数学考试中独有的,在国内的考试中不常见。这类题目和数学运运算毫无关联,题目较少,但十分新颖。乍一看让人有些迷惑不解,其实只要掌握了恰当的方法,解题十分容易。那么,SAT数学逻辑推理题如何解题呢?
例题:
Family
Numbers of Consecutive
Nights
Jackson
10
Callan
5
Epstein
8
Liu
6
Benton
8
The table above shows the number of consecutive nights that each of five families stayed at a certain hotel during a 14-night period. If the Liu family’s stay did not overlap with the Benton family’s stay, which of the 14 nights could be a night on which only one of the five families stayed at the hotel?
A. The 3rd B. The 5th C. The 6th D. The 8th E. The 10th
解答:此题只要借助线段,便一目了然了。既然原文说“the Liu family’s stay did not overlap with the Benton family’s stay”,而且两家刚好加在一起正好是14晚,那么不妨将这14晚设为一段长14cm的线段,从6cm处分割:
Liu Benton family family︳______ ____︳_________________︳
0 6cm 14cm
︳________10cm__________︳
︳________10cm__________︳
上题的解答过程就是利用逻辑推理的过程,由于Jackson family是剩余家庭里呆得时间最长的,所以只要从他家看起即可。该题可以简单转化为一段长10cm的线段在14cm范围内左右移动,要么露出最左面的 0~4cm空间(不包括4),要么留出最右面的10~14cm(不包括10)。所以没有被 Jackson family所覆盖的只有这两个区间,也就是说只有一家居住的只能是前三天或后三天,答案为A。
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