狒狒上一道逻辑题目

 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

我选的C，答案给的是B， 不晓得为何选B。

答案就是C。

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。

To xfi883 -

谢谢~刚贴的两道题看到你很快帮助回复了。

请问下雨的这个确定是C吗？狒狒给的答案错误啊。

谢谢edmundshi的解答。

看了下讨论的贴，又看了看题目，最后觉得应该是B。

知道了RAINFALL和LOW PRESSURE的关系，再知道RAINFALL和THUNDERSHOWER的关系，就能推出LOW PRESSURE情况下THUNDERSHOWER的关系。

好绕的一个题。