Question

这是 gMAT 问题。。 怎

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?

Answer 1

ps题给个选项就更好了！
题目：一个店卖报，A报1刀每份，B报1.25刀每份。那天没有其他报纸卖。如果该店总收入的R%来自a报纸的销售，B报纸占销量的P%，求用P表示R。
解： 设一共买了X份报纸
由题意得：A销量(100%-P%)X,B销量P%X
R%=A总利润除以(A+B）的总利润

R%=1*(100%-P%)X/(1*(100%-P%)X+1.25*P%X)
提出X约了，再化简一下
最后R%=(100%-P%)/(100%+0.25P%)