各位大牛，帮小弟解几道数学题吧 ，多谢

han7262929

因为自己的语言基础有点差 ，对数学题得理解感觉有点难，做PREP 有几道题错了，大牛们帮我分析下各题吧，多谢~~~~\(^o^)/~

·1. in the XY-plane, what is the y-intercept of line L?

（1）the slope of line L is 3 times its y-intercept

·(2) the x-intercept of line L is -1/3 ·正确答案E

·2，all of the stocks on the over-th-counter market are designated by either a 4-letter or a 5 letter code that is created by using the 26 letters of the alphabet,which of the following gives the maximum
number of different stocks that can be designated with these codes?

·A 2(26^5)·B,26(26^4)·C,27(26^4)·D.26(26^5)·E.27(26^5)·正确答案：C

·3,rates for having a manuscript typed at a certain typing service are $5 per page for the first time a page is typed and
$3 per page each time a page is revised. If a certain manuscript has 100 pages, of which 40 were revised only once,
10 were revised twice, and the rest required no revisions, what was the total cost of having the manuscript typed?

A,$430·B,$620·C,$650·D,$680·E,$770·答案：D

·4. the residents of town X partivipated in a survey to determine the number of hours per week each resident spent
watching television. The distribution of the results of the survey had a mean of 21 hours and a standard deviation
of 6 hours . the number ofhours that pat, a resident of town X,watched television last week was between 1 and 2
standard deviations below the mean , which of the following could be the number of hours that pat watched
televison last week?

·A 30·B,20·C18·D12·E6·答案：D

han7262929

最好写上详细的怎么做的哈，多谢了~~~~~~~~~~

han7262929

每题提示下也行啊，怎么没人啊。。。。

liuqiangde

http://forum.chasedream.com/GMAT_Math/thread-531381-1-1.html?postid=14923666&searchmode=TopicContent&searchtext=y intercept of line l