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标题: gwd-29 Q35 [打印本页]

作者: eshopaholic 时间: 2010-12-6 19:41
标题: gwd-29 Q35
InPatton City, days are categorized as having heavy rainfall (more than twoinches), 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 norainfall. In 1990, there were fewer dayswith light rainfall than in 1910 and fewer with moderate rainfall, yet totalrainfall for the year was 20 percent higher in 1990 than in 1910.

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

A. thenumber of days with heavy rainfall was lower in 1990 than in 1910
B. thenumber of days with some rainfall, but no more than two inches, was the same in1990 as in 1910
C. thenumber of days with some rainfall, but no more than two inches, was higher in1990 than in 1910
D. thetotal number of inches of rain that fell on days with moderate rainfall in 1990was more than twice what it had been in 1910
E. theaverage amount of rainfall per month was lower in 1990 than in 1910

答案A，我觉得B

请指点下

作者: eliasfan 时间: 2010-12-6 21:27
some rainfall （no more than two inches）includes MR & LR， but in the article MR & LR in 1990 are both no more than those in 1910 ,so B is wrong
Total Rain day=HR+MR+LR +MR
in 1990 LR & MR are fewer than those in 1910
so it is possible that thenumber of days with heavy rainfall was lower in 1990 than in 1910
A correct

作者: sdcar2010 时间: 2010-12-6 22:11
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.

作者: sdcar2010 时间: 2010-12-6 22:14

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.

A is correct to point out the first possibility with very heavy rainfalls in fewer days.

-- by 会员 sdcar2010 (2010/12/6 22:11:01)

I was leaning to D at first. But the math shows that it is impossible to have twice amount of rain with even the same number of moderate rainfall days. So I crossed out answer D. If D says the light rainfall amount in 1990 is twice that in 1910, that would be possible.

作者: frank6895817 时间: 2011-7-18 09:51
ok

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