Feifei 逻辑70---揣摩

girlwithwings

70. A low-pressure weather system is approaching Plainville; rainfall results from about 70 percent of such systems in the Plainville
area. Moreover, the current season, spring, is the time of year in which thundershowers, which sometimes result from low-pressure systems, are most likely to occur in Plainville.


Knowing which one of the following, in addition to the information above, would be most useful for determine the probability that Plainville
will have a thundershower soon?


A.       the percentage of thundershowers in Plainville
that occur in the spring
B.        the percentage of spring rainfalls in Plainville
that are thundershowers
C.        the percentage of thundershowers in Plainville
that result from low-pressure systems
D.       whether low-pressure systems in other areas are associated with rainfall

E.        whether Plainville
has more or fewer thundershowers each spring than do near by towns


参考答案：C

这题的问题 。。。determine the probability that Plainville will have a thundershower soon?

言下之意是求 低气压影响下的thundershower的概率？ 是的话可以认同答案C

设 rainfall 为C，低气压下的rainfall 为B，低气压下的thundershower为A

题目求的若是 A/C 的话， 可以由 B/C * A/B 得到， B/C为已知条件，只要求A/B。

不是的话（只是单单thundershower的概率），不能认同C。

这样的想法不知道对吗？

大家对此题有何看法？

prayer

直接忽略rainfall。

A low-pressure weather system is approaching Plainville;这句很关键，低压要来了，后面是推测不久就有雷暴，当然是让你联系低压和雷暴的关系。其他不用考虑

girlwithwings

所以是问题 the probability that Plainville will have a thundershower
+ 第一句话 A low-pressure weather system is approaching 直接等于
= C  the percentage of thundershowers in Plainville that result from low-pressure systems
文中其他信息就没什么关系，是吗？

prayer

所以是问题 the probability that Plainville will have a thundershower
+ 第一句话 A low-pressure weather system is approaching 直接等于
= C  the percentage of thundershowers in Plainville that result from low-pressure systems
文中其他信息就没什么关系，是吗？

-- by 会员 girlwithwings (2009/12/23 2:35:24)

是的，基本上一点关系都没，就是为了迷惑选项的