GWD数学2009第一套。。。求救。。。

WesternCder

今天做了GWD数学第一套。。。惨不忍睹。。。

Q10:
A set of numbers has the property that for any number t in the set, t + 2 is in the set.
If –1 is in the set, which of the following must also be in the set?

I.-3
II.1
III.5

A.I only
B.II only
C.I and II only
D.II and III only
E.I, II, and III

我觉得是C，答案是D

Q16:
If J, S, and V are points on the number line, what is the distance between S and V?
(1)The distance between J and S is 20.
(2)The distance between J and V is 25.

选E哦。。。但我怎么看都觉得应该选C。。。

Q30:
Joanna bought only $0.15 stamps and $0.29 stamps.
How many $0.15 stamps did she buy?
(1)She bought $4.40 worth of stamps.
(2)She bought an equal number of $0.15 stamps and $0.29 stamps.

这题（2）为什么也对呢。。。 选D

Q35:
What is the median number of employees assigned per project for the projects at Company Z?
(1)25 percent of the projects at Company Z have 4 or more employees assigned to each project.
(2)35 percent of the projects at Company Z have 2 or fewer employees assigned to each project.

选C。。。

amorer

那个弱弱的说一下
Q35：25%+35%=60%
题目中的median是中位数的意思
即找中间那个数: http://baike.baidu.com/view/170892.htm?fr=ala0_1_1
自然落到40%的3那个段数上
>4   25%
3      40%
<2   35%

zengzihao

Q10: 只说了t在能推出t+2在，没说反过来也成立，所以1不对，-1+2=1，所以2对，1+2=3，3+2=5，所以3对
Q16:没说按顺序排列，你自己画两个数轴，一个是J,S,V这样排列，一个是V,J,S这样排列，结果一个得5，一个得45，所以E
Q30：这题选D??我觉得单独2推不出来啊
Q35：同意楼上的解答

mereimoun

Q35: 35% have 2 or less, 25% have 4 or more means 50% have 3 assigned, so median has to be 3

quellekind

Q10  -1+2=1 1+2=3 3+2=5 所以1和5都在
Q16   1不能确定 2不能确定 1+2的话可以为45 也可以为5 所以选E
Q30  1. 0.15X+0.29Y=4.4 X y 均要为整数 只有X=Y=10
        2.(0.15+0.29)X=4.4 X=10
        所以选C
Q35 没看懂。。