求解一道GWD数学~谢谢大家~

ClaudiaJL

我化简到r=100（100-p）/100-0.25p 就化简不下去了~

-- by 会员 zhangtysun (2012/9/10 16:01:38)

不要忧伤 我来救你？？！！！
正确题目如下：
Last Sunday a certain store sold copies of Newspaper Afor $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 ofnewspaper A, which of the followingexpresses 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)
你列式子无问题，此楼题目稍不对。