taotao 版GWD 第11套数学~求好心人指导！

gmet

Q8:
When positive integer x is divided by 5, the remainder is 3; and when x is divided by 7, the remainder is 4.When positive integer y is divided by 5, the remainder is 3; and when y is divided by 7, the remainder is 4.If x > y, which of the following must be a factor of x - y?


D.12
E.15
F.20
G.28
H.35
I.2

余数问题啊……纠结,
Q23:
One kilogram of a certain coffee blend consists of x kilogram of type I coffee and y kilogram of type II coffee.The cost of the blend is C dollars per kilogram, where C = 6.5x + 8.5y.Is x < 0.8?
(1)y > 0.15
(2)C ≥ 7.30

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.


毫无头绪，答案是C
Q28:
A certain company sold 800 units of its product for $8 each and 1,000 units of its product for $5 each.If the company’s cost of producing each unit of its product was $6, what was the company’s profit or loss on the 1,800 units of its product?


A.$1,600 loss
B.$600 loss
C.No profit or loss
D.$600 profit
E.$1,600 profit


为何答案是A?
Q36:
If x, y, and k are positive numbers such that (
)(10) + ()(20) = k and if x < y, which of the following could be the value of k?

A.10
B.12
C.15
D.18
E.30
这个答案是D

catharine6699

Q8   X和Y都可以表示成35n+18~所以x-y是35的倍数～所以选H

请问这个35n+18是怎么弄出来的啊？？

gmet

太感谢了！！！  
Q36题粘公式的时候没显示，括号里是（x/(x+y))
原题就是
Q36:
If x, y, and k are positive numbers such that (
x/x+y)(10) + (x/x+y )(20) = k and if x < y, which of the following could be the value of k?麻烦您再给看一下？

doreendu0809

Q8:
When positive integer x is divided by 5, the remainder is 3; and when x is divided by 7, the remainder is 4.When positive integer y is divided by 5, the remainder is 3; and when y is divided by 7, the remainder is 4.If x > y, which of the following must be a factor of x - y?


D.12
E.15
F.20
G.28
H.35
I.2

X和Y都可以表示成35n+18~所以x-y是35的倍数～所以选H
Q23:
One kilogram of a certain coffee blend consists of x kilogram of type I coffee and y kilogram of type II coffee.The cost of the blend is C dollars per kilogram, where C = 6.5x + 8.5y.Is x < 0.8?
(1)y > 0.15
(2)C ≥ 7.30

这题有一个暗含条件是x+y=1的，带入就可以了，答案应该是B
Q28:
A certain company sold 800 units of its product for $8 each and 1,000 units of its product for $5 each.If the company’s cost of producing each unit of its product was $6, what was the company’s profit or loss on the 1,800 units of its product?


A.$1,600 loss
B.$600 loss
C.No profit or loss
D.$600 profit
E.$1,600 profit

答案不对应该是D吧
Q36:
If x, y, and k are positive numbers such that (
)(10) + ()(20) = k and if x < y, which of the following could be the value of k?

A.10
B.12
C.15
D.18
E.30
你这道题目好像有点问题~首先由式子可以看出10<k<20的然后x<y的话可以得出k>15,所以就18了～