求罗技高人

zpleo

题不难懂，可我就不明白为什么选A啊。求高人解答

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

sdcar2010

This is a math problem.

In 1990 there was only one day wth heavy rainfall.  But the rainfall on that day = 100 inches. In 1910 there were 10 days of heavy rainfall.  But the rainfalls were 2.1 inches for each of the ten days. So total rainfall from the heavy rainfall = 21 inches. Then combined with moderate and light rainfalls, it is possible that the total rainfall in 1990 is 20% than that in 1910.