请教GWD中的几道数学题

以下是我做GWD时遇到的和答案不一样而我又实在想不通的题目，请nn们不吝赐教

GWD 4-24（答案是C,我不知道是不是我钻了什么牛角尖，总之怎们看都是B)

At a certain company, each employee has a salary grade s that is at least 1 and at most 5.  Each employee receives an hourly wage p, in dollars, determined by the formula p = 9.50 + 0.25(s – 1).  An employee with a salary grade of 5 receives how many more dollars per hour than an employee with a salary grade of 1?

A.    $0.50

B.     $1.00

C.     $1.25

D.    $1.50

E.     $1.75

GWD 4-36 (怎么想怎么觉得2已经很充分，可以 推出n=180，但是答案是C)

If n is an integer and 100 < n <200, what is the value of n?

(1) n/36 is an odd number

(2) n/45 is an even number

GWD 6-6,6-7,6-8. 答案分别是CDD,有没有错？如果没有，还请指点一下。

6。The ratio of the number of red cars in a certain parking lot to the number of black cars is 3 to 8.  If there are 72 black cars in the lot, how many red cars are there in the lot?

A. 11    B. 15     C. 21     D.27     E.32

7.What is the value of │x + 7│?

(1)  │x + 3│= 14

(2)   (x + 2)² = 169

8.The figure above represents a square garden that is divided into 9 rectangular regions with indicated dimensions in meters.  The shaded regions are planted with peas, and the unshaded regions are planted with tomatoes.  If the sum of the areas of the regions planted with peas is equal to the sum of the areas of the regions planted with tomatoes, what is the value of x?

GWD 8-12 (答案是E????)

In the xy-plane, region R consists of all the points (x,y) such that 2x+3y=6. IS the point (r,s) in the region R?
(1) 3r+2s=6
(2) r=3 and s=2

GWD 10-13 (答案是D????)

If x and y are positive, is 3x>7y?
(1) x>y+4
(2) -5x<-14y

GWD 10-24 (答案是C????)

If w and c are integers, is w>0?
(1) w+c>50
(2) c>48

我想有的可能是因为我脑子一时转不过弯来，但是实在是想不通了，也不想自己想了，请各位再帮我确认以下以上答案，谢谢了先。

答案错了

有问题可以去

http://forum.chasedream.com/dispbbs.asp?boardID=22&ID=58619&page=1