GWD数学一道

jbc88

Q28:
Last Sunday a certain store sold copies of Newspaper A for $1.00 each and copies of Newspaper B for $1.25 each, and the store sold no other newspapers that day.  If r percent of the store’s revenues from newspaper sales was from Newspaper A and if p percent of the newspapers that the store sold were copies of newspaper B, which of the following expresses r in terms of p?

A.    100p / (125 – p)
B.    150p / (250 – p)
C.    300p / (375 – p)
D.    400p / (500 – p)
E.    500p / (625 – p)

longee

p代表的不是你说的那个含义，你再看看题

longee

...

machao924

实在想不明白第一道题答案为什么是D。

我自己的看法，只有两种报纸，如果报纸A的销售金额占r percent而报纸B的销售金额占p percent。那r+P=100，所以r=100-P。跟销售单价有什么关系？用的着那么麻烦地倒来倒去吗？

烦请各位大牛指点，谢谢

magicstar

呵呵～ “原谅” 你了，LZ 加油吧

jbc88

不会吧。。我复制下来的

jbc88

。。。。复制下来的。。

magicstar

呵呵～ 我也算了许久

zgy32041

第一道，LZ 抄错题了吧，我找的题是
Last Sunday a certain store sold copies of Newspaper A for $1.00 each and copies of Newspaper B for $1.25 each, and the store sold no other newspapers that day. If r percent of the store’s revenues from newspaper sales was from Newspaper A and if p percent of the newspapers that the store sold were copies of newspaper A, which of the following expresses r in terms of p?
A. 100p / (125 – p)
B. 150p / (250 – p)
C. 300p / (375 – p)
D. 400p / (500 – p)
E. 500p / (625 – p)

OA is D.

-- by 会员 magicstar (2010/10/23 17:11:39)

原来是抄错题了。。这个LZ浪费了我将近半个小时。。。试了各种方法

zgy32041

Q28:
Last Sunday a certain store sold copies of Newspaper A for $1.00 each and copies of Newspaper B for $1.25 each, and the store sold no other newspapers that day.  If r percent of the store’s revenues from newspaper sales was from Newspaper A and if p percent of the newspapers that the store sold were copies of newspaper B, which of the following expresses r in terms of p?

A.    100p / (125 – p)
B.    150p / (250 – p)
C.    300p / (375 – p)
D.    400p / (500 – p)
E.    500p / (625 – p)

-- by 会员 jbc88 (2010/10/23 15:22:05)

这道题答案是哪个？？请楼主确认题目有没有错误，貌似求不出正解