[求助]请教一道逻辑题

cjmizi

In Patton City, days are categorized as having heavy rainfall (more than tow inches), moderate rainfall (more than one inch, but no more than tow 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 as 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 1910.

 

答案是A，
            我是用排除法选择的A 但是细看后发现好像应该是the number of days with heavy rainfall was lower in 1910 than in 1990 ！.请大家给点意见

niaoniao36

轻度降水和中度降水的天数和总降水量之间的关系，还需要有每次降水的inch数这个变量。

所以，就算1990年heavy rainfall得降水量要大于1910年heavy rainfall的降水量，都有可能1990年下heavy rain的天数少于1910年相应的天数。举例：1990年的总降水量为30000， 却总共下了3场heavy rainfall，但是每场都是10000 inch。而1910年，虽然总降水量大个比方为3000，但下了30场，每场100，所以。。。。答案自然就是A啦。

jodiewang

But how can we eleminate answerD? is there any formula?

cjmizi

非常感谢niaoniao36同学 解释得非常清楚！ 我明白了