- UID
- 486530
- 在线时间
- 小时
- 注册时间
- 2009-10-30
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
由于数学比较差，把PREP破解的800多道题都做了，可是有几道题还是一头雾水，希望热心的同学们帮着看看，谢谢啦(*^__^*) ！
1．
If t is a positive integer and r is the remainder when t2 + 5t + 6 is divided by 7, what is the value of r ?
(1) When t is divided by 7, the remainder is 6.
(1)When t2 is divided by 7, the remainder is 1.
2．
In the xy-coordinate plane, line m and line k intersect at the point (4, 3).Is the product of their slopes negative?
(1)The product of the x-intercepts of lines m and k is positive.
(2)The product of the y-intercepts of lines m and k is negative.
3．
If the prime numbers p and t are the only prime factors of the integer m, is m a multiple of p2t ?
(1) m has more than 9 positive factors.
(2) m is a multiple of p3.
4．
Of the 1,400 college teachers surveyed, 42 percent said that they considered engaging in research an essential goal.How many of the college teachers surveyed were women?
(1) In the survey, 36 percent of the men and 50 percent of the women said that they considered engaging in research an essential goal.
(2) In the survey, 288 men said that they considered engaging in research an essential goal.
5．
Each employee of Company Z is an employee of either Division X or Division Y, but not both.If each division has some part-time employees, is the ratio of the number of full-time employees to the number of part-time employees greater for Division X than for Company Z ?
(1) The ratio of the number of full-time employees to the number of part-time employees is less for Division Y than for Company Z.
(2) More than half of the full-time employees of Company Z are employees of Division X, and more than half of the part-time employees of Company Z are employees of Division Y.
这五道题不会做啊，先不说答案了，大家看看怎么选，想和大家讨论下。
然后这道觉得很诡异，大家看看！
6．
If the drama club and music club are combined, what percent of the combined membership will be male?
(1)Of the 16 members of the drama club, 15 are male.
(2)Of the 20 members of the music club, 10 are male.
这道题则是非常吃惊，more than 怎么会和at least 同意呢？是不是题错了？？？
7．
If a certain company purchased computers at $2,000 each and printers at $300 each, how many computers did it purchase?
(1)More than three printers were purchased.居然包括3台！！！！！
(2)The total amount for the purchase of the computers and the printers was $15,000.
【答案】E
【思路】
(1)只表示printer 多買3台以上,insufficient
(2) 2000c+300p=15000,無法得知computer數量,insufficient
(1)+(2) 有可能是computer 3台 印表機 30台or computer 6台 printer 10台,insufficient
8．
If m is a positive odd integer between 2 and 30, then m is divisible by how many different positive prime numbers?
(1) m is not divisible by 3.
(2)m is not divisible by 5.
【答案】A
【思路】
2<m<30
{3,5,7,9,11,13,15,17,19,21,23,25,27,29}
(1) m excludes {3,6,9,12,15,18,21,24,27}={5,7,11,13,17,19,23,25,29} 全部只可以被自己和1除
(2) m excludes {5,10,15,20,25}={3,7,9,11,13,17,19,21,23,27,29} 21除了自己和1還可以被7除这里的解释我觉得有异议啊！！！虽然含有如9=3*3， 21=3*7等数，那里都是重复的质因子啊，我觉得仍然可以回答问题的，所以选D，你们觉得呢？？？
9．
On the number line shown, is zero halfway between r and s ?
(1) s is to the right of zero.
(2) The distance between t and r is the same as the distance between t and -s.
这道题则是弱弱地问啦，为什么不选B啊！！！！
不好意思，问的有点多，不过我觉得这几道题都挺好的，大家看看吧，不胜感激！
|
|
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2010-9-9 20:06:27
收藏
收藏
楼主
