Prep和JJ三题

saugaone

WD 9

Q20:

	Favorable	Unfavorable	Not Sure
Candidate M	40	20	40
Candidate N	30	35	35

The table above shows the results of a survey of 100 voters each responded “favorable” or “unfavorable” or “not sure” when asked about their impressions of candidate M and of candidate N.  What was the number of voters who responded “favorable” for both candidates?

(1)   The number of voters who did not respond “favorable” for either candidate was 40.

(2)     The number of voters who responded “unfavorable” for both candidates was 10.

                  

Answer: A

然后是JJ

4、

Project	yes	no	unsure
M	500	200	100
R	400	100	300

说调查800个学生 found project M or R, 他们有三种不同回答：yes, no, unsure.现在有200个学生
   only say “yes” for Project M, 问有多少个学生no say “yes” either for M or for R

Answer:200? 我不理解

Prep:

Amy's grade was the 90 percentile of the 80 grades for her class. of the 100 grades from another class, 19 were higher than Amy's, and the rest were lower. if no other grade was the same as Amy's grade, then Amy's grade what percentile of the grades of two classes combined?  72nd, 80th, 81st, 85th, 92nd

Please NN help

然后是JJ

4、

Project	yes	no	unsure
M	500	200	100
R	400	100	300

说调查800个学生 found project M or R, 他们有三种不同回答：yes, no, unsure.现在有200个学生
   only say “yes” for Project M, 问有多少个学生no say “yes” either for M or for R

Answer:200? 我不理解

Prep:

Amy's grade was the 90 percentile of the 80 grades for her class. of the 100 grades from another class, 19 were higher than Amy's, and the rest were lower. if no other grade was the same as Amy's grade, then Amy's grade what percentile of the grades of two classes combined?  72nd, 80th, 81st, 85th, 92nd

Please NN help

Prep:

这个替我看的的糊里糊涂的，看不大同，请NN解释提议：

the figure shows the top side of a circular medallion made of a cirlular piece of colored glass surrounded by a metal frame, represented by the shaded region. if the radius of the medallion is r centimeters and widthe of the medal frame is s centimeters, then in term of s and r, what is the area of the metal frame, in square centimeters?

[此贴子已经被作者于2007-10-22 3:12:09编辑过]

Pinpinpink

第一道：要问的是给MN都投了favor票的人数，（1）条件说没有给其中一个投favor票的人的数是40，从另外一个角度来看，就是说这些人肯定都投了一个favor票给其中之一，人数是40，那么70个里面排除了40个，那么就剩30个一定是给两个都投的啦！题目中用的either很诡异！我是根据答案来理解的！我也很菜！

第2道题目no say “yes” either for M or for R没看明白！

Prep那一道：在80个人那个班里面，有8个人分数比Amy高，80（1-90%）；两个班放在一起，一共就有19+8=27个人的分数比他高，Amy就排在180-27的位置，算百分比就是（180-27）/180=85%

自己瞎做的，供楼主参考而已！错了欢迎批评！

solososo

有两百人只对M说yes，说明对两个项目都yes的人有500-200=300人，所以只对R说yes的人数是400-300=100人，那么我们把八百人总共分成四类：1都说yes，2只说Myes，3只说Ryes，and对两个项目都没说yes的（我们本题的答案）。四个选项没有重叠，答案就出来了

tinagmat2007

调查800学生那个题目其实是故意复杂化了，你只要看回答yes的，把回答no和unsure的看成一个整体。由only 200人推出（500-200）是400和500的交集，那么no和unsure的就是800-（200+300+100）就行了，说着麻烦，画个图就清楚了

Ironpanda

留名

saugaone

qing NN zhi jiao

zhouium

the figure shows the top side of a circular medallion made of a cirlular piece of colored glass surrounded by a metal frame, represented by the shaded region. if the radius of the medallion is r centimeters and widthe of the medal frame is s centimeters, then in term of s and r, what is the area of the metal frame, in square centimeters?

一个奖牌里面是glass,外面包了一层metal frame,glass部分半径为r, medal frame的width是s, 求frame 的面积

pie(r+s)^2-pie*r^2

saugaone

我就是不明白，如何确定他们的交际是300，300个人既选了M也选了R的Yes，请指教

lisy

以下是引用zhouium在2007-10-22 4:11:00的发言：

the figure shows the top side of a circular medallion made of a cirlular piece of colored glass surrounded by a metal frame, represented by the shaded region. if the radius of the medallion is r centimeters and widthe of the medal frame is s centimeters, then in term of s and r, what is the area of the metal frame, in square centimeters?

一个奖牌里面是glass,外面包了一层metal frame,glass部分半径为r, medal frame的width是s, 求frame 的面积

pie(r+s)^2-pie*r^2

应该是2s

pie(r+2s)^2-pie*r^2

这类题最近JJ经常出现，要注意了

iriswongj

请问楼上的，为什么要加2S呢？算面积不是用pai乘以radius就好了么？包了金属之后大圆的半径是(r+s)，原来的答案是对的吧？

如果错的话恳请NN指点。