GWD29-Q35求助~

CrapSociety

38: GWD-29-Q35（归纳）
In Patton City, days are categorized as having heavy rainfall (more than two inches), moderate rainfall (more than one inch, but no more than two inches), light rainfall (at least a trace, but no more than one inch), or no rainfall.In 1990, there were fewer days with light rainfall than in 1910 and fewer with moderate rainfall, yet total rainfall for the year was 20 percent higher in 1990 than in 1910.

If the statements above are true, then it is also possible that in Patton City

A.the number of days with heavy rainfall was lower in 1990 than in 1910

B.the number of days with some rainfall, but no more than two inches, was the same in 1990 as in 1910

C.the number of days with some rainfall, but no more than two inches, was higher in 1990 than in 1910

D.the total number of inches of rain that fell on days with moderate rainfall in 1990 was more than twice what it had been in 1910

E.the average amount of rainfall per month was lower in 1990 than in 1910
我选的D，错了，正解是A。。。怎么可能。。。A首先被我排出了。。。

CrapSociety

虽然题目中是rainfall选项中是the number of days...但是A还是不太可能对啊啊啊。。。

wenyiwendy

If all the heavy rainfall days in 1990 had 100 inches of rain and all the heavy rainfall days in 1910 had no more than 3 inches . . .

wenyiwendy

A is correct

There are only two likely possibilities for 1990 to have more total rainfalls than 1910:

1) Total rainfalls from heavy rainfalls is bigger in 1990 than in 1910.  This could be done either by very heavy rains in a few days in 1990 or with more heavy rainfalls days in 1990
2) Total rainfalls from moderate/light rainfalls is bigger in 1990 than in 1910.  This possibility sounds counterintuitive but is mathmatically possible.  Keep in mind the definition of moderate/light rainfalls is based on a range. It is conceivable that a moderate rainfalls day could have either 1.9 inch or 1.1 inch of rain.  So if all the moderate rainfall days in 1990 had 1.9 inch while all the moderate rainfall days in 1910 had only 1.1 inch, the total rainfall in 1990 could be bigger than in 1910.

Answer A points out the first possibility and is the right answer.

CrapSociety

呃。。。这我倒是明白哇。。。只是A选项并没有挑明，我做题时没敢太YY。。。

xiaoguolulu

A is correct

There are only two likely possibilities for 1990 to have more total rainfalls than 1 ...
wenyiwendy 发表于 2012-10-11 06:25

多谢，很厉害的NN，每每拜读你的解释都要读很多遍才懂，哈不过精华就是这样。这题和我以前遇到的不一样，possible，选的是可能有机会正确的，其余全是不可能发生的？？对不？其实对于这题我有疑惑的是D选项，因为两个年份只是moderate rainfall的day不同，或者说1910比1990天数多，但因为每天的平均降雨量（inch）不知道所以1990的moderate rainfall的总降雨量（我把它理解成D中的total number of inches of rain）还是可能比1910的多的。那么

D. the total number of inches of rain that fell on days with moderate rainfall in 1990 was more than twice what it had been in 1910
也有可能对，但后来又想到m r的范围是（1,2）所以不可能超过两倍，不知道我理解有没有误？

kaneroy

A首先排除的飘过。。。还是觉得A很奇怪啊，为什么不说days in 1990多余1910,一定要说少于呢。还要考生自己YY虽然天数少但是雨量多。。
GWD的CR答案真心绕- -！

willgoeu

终于懂了，太绕！谢谢