[求助]自尊心受挫！大牛帮忙看看GWD的数学题

把第一道题和后面两道删掉了，谢谢2楼和3楼朋友的解答，但还剩满多题不解，不知是不是答案的问题 ：（

Q24: （难道有陷阱这道题，
        不就是分别将5 和 1带到式子里，所得的结果
        相减吗？
        我的答案是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

Q29:
        （答案是B，我选A了，因为
        设97年rent =a ，
        那么99 年的rent 应为
        （1+ x%-y%）a ，
        只要99的值/97年的值大于1，就可知99年的比97年的多。

        就是说，要知道
        x% -y% >0, A 正好解答了。
        ）

The annual rent collected by a corporation from a certain
building was x percent more in 1998
than in 1997 and y percent less in
1999 than in 1998.  Was the annual rent collected by the corporation from
the building more in 1999 than in 1997?

(1)
             
x > y

(2)
             
xy/100 < x – y

Q36: （这道题给C，觉得，有问题，因为 B 单独就可以。
        n/45=2，4，6….且100
<n< 200,所以取n/45=4，
        n=180）

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

(1)
          n/36 is an odd integer.

(2)
          n/45 is an even integer

...这么多问题....

第一题,能整除8的数是所有的双数+(八的倍数-1)

因为n*(n+2),所以n为双数

因为n+1,所以n为8的倍数-1,必为奇数,两者不会重复

所以1到96包括了48个双数以及12个(8的倍数-1),一共是60个

GWD  4  Q17: （如下是两道关于中位数的题，蒙了！）

The number of defects in the first five cars to come through a new production line are 9, 7, 10, 4, and 6, respectively.  If the sixth car through the production line has either 3, 7, or 12 defects, for which of theses values does the mean number of defects per car for the first six cars equal the median?

I.                   3

II.                7

III.             12

A.         I only

B.         II only

C.         III only

D.         I and III only

E.         I, II, and III

我怎么觉得这个应该选择E

三个数字带进去后 中数和平均数值都相等