求教NN帮忙解答：降雨量 逻辑推理数学题

中国故乡的云

GWD-29-Q35

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

请NN帮忙解答，衷心感谢！

中国故乡的云

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

如果 lower是higher 就好了。。。。

jameshoo

A 的lower 也是可能的，比如假设极端情况：90年虽然下heavy rain的天数少，但每次都下他个一两千inches,最后还是可能导致90年总降水量为10年的1.2倍。

B和C和题目叙述的事实不符：题目说90年下小雨的天数少于10年，90年下中雨的天数也小于10年，所以90零年下小雨和下中雨的天数肯定小于10年下小雨和中雨的天数。

D的错误在于90年的中雨不可能是10年中雨（注意中雨的定义是大于1 inch小于等于2 inches）的两倍，否则90年的中雨就成了大雨（注意大雨的定义）

E错误很明显，90年全年降雨多于10年，所以月均降雨量也多于10年

[此贴子已经被作者于2009-4-13 13:13:06编辑过]

中国故乡的云

谢谢 LS的律师同学啊，呵呵！

不怕下雨天数少，就怕哪天中头彩，1天下个500W，O(∩_∩)O~