GWD 12 数学是不是答案有错的呀 各位帮帮忙吧 马上就考了啊

LeannaChina

Q28:
Each of the 30 boxes in a certain shipment with either 10 pounds or 20 pounds, and the average (arithmetic mean) weight of the boxes in the shipment is 18 pounds.If the average weight of the boxes in the shipment is to be reduced to 14 pounds by removing some of the 20-pound boxes, how many 20-pound boxes must be removed?


A.4

B.6
C.10

D.20

E.24

我怎么算是12呢 可选项没有。。。。


Q10:
















In the figure shown, two identical squares are inscribed in the rectangle.If the perimeter of the rectangle is 18√2, then what is the perimeter of each square?


A.8√2

B.12
C.12√2

D.16

E.18

我算是24  可是选项也没有 啊 。。。唉


Q32:
Seven different numbers are selected from the integers 1 to 100, and each number is divided by 7.What is the sum of the remainders?
(1)The range of the seven remainders is 6.
(2) The seven numbers selected are consecutive integers.

data sufficiency 我认为呢 1 和2  说的不是一回事吗 怎么选b 不选a 呢 ？？？？

各位大侠谢谢啦 ！！

毛毛carina

LZ，之前发过两个数学帖子在语法区，我今天早上已经帮你移到数学区啦，请去那里查看回复吧~~估计你没有看到之前给你发的移动主题通知，所以这个我就暂时留着，半个小时候也帮你移动过去咯。

以后注意哈，问什么问题都要到相关专区发帖哦，比较方便讨论~~

LeannaChina

哦 ~~这样子 还有这一说  不好意思啊 呵呵 下不为例啊

LeannaChina

只能重新发 才能移动吗 不好意思啊 新来的 请多指教。，，，嘿嘿

zongheimun

Q 28, 应该理解为把20磅重的箱子拿掉几个，而不是换成10磅，所以箱子总数量减少了
10磅的箱子依旧是6个，设搬走X个20磅重的后， [6*10+（24-x）*20]/（30-x）=14，
求得 x=20，之前20磅的有24个，所以答案是 4，remove掉 4个

LeannaChina

我认为你说的很有道理 恩  可是答案是20 呀 是不是答案错了呢~~谢谢你拉

zongheimun

可能把 出题人把剩下的数量当成应该remove掉的了？

mirageseeker

第一题:

x+y=30
10x+20y=18(x+y)
10x+20(y-n)=14(x+y-n)

Use 2nd equation - 3rd equation:

20n=4x30+14n
n=20

第二题没有图啊？
第三题 a and b are definitely different.

We know the remainder can be from 0 to 6, if remainder is 0,1,1,1,1,1,6, the range is 6; if remainder is 0,1,2,3,4,5,6, the range is also 6. So option a is telling me nothing. Option b is valid because you can only have ONE outcome, which is 0,1,2,3,4,5,6

LeannaChina

图图 是这里的第十题的  不好意思哈 粘贴 贴不过来。。。呵呵 麻烦您啦