ChaseDream

标题: FeiFei 70 很困惑大家帮我看看吧 [打印本页]

作者: elodie 时间: 2009-9-23 11:30
标题: FeiFei 70 很困惑大家帮我看看吧

70. A low-pressure weather system is approaching lainville; rainfall results from about 70 percent of such systems in the lainville 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 lainville.

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

A. the percentage of thundershowers in lainville that occur in the spring

B. the percentage of spring rainfalls in lainville that are thundershowers

C. the percentage of thundershowers in lainville that result from low-pressure systems

D. whether low-pressure systems in other areas are associated with rainfall

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

参考答案：C

思路：文中给出两个条件，1是低压天气将到达，而70%的低压天气导致降雨，2是现在正是1年中雷阵雨最多的季节且雷阵雨有时也是由于低压天气导致；答案（C）给出了低压天气导致雷阵雨的比率，用70%乘以这个比率，就可以得到下雷阵雨的概率了。

A、B没能和低压天气联系起来，D、E为无关选项

以上是费费详解版的分析（选C），而参考答案给的是B

我想问的是

如果选C的话仅凭选项不就可以得出下雷阵雨的概率了么，为什么还要乘以70%呢

而选B的话，乘以70%的说法似乎还比较有道理

这道题正确答案是哪个呢，大家帮忙看看吧

作者: jillchenyy 时间: 2009-9-23 13:22
同问，请高手

作者: myoka 时间: 2009-11-4 22:49
B is the right answer.

C的意思是有百分之几的雷阵雨是来自于低气压。并不是说低气压会带来雷阵雨的可能性。

欢迎光临 ChaseDream (https://forum.chasedream.com/)