求教~~！

sierrapan

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?
 
 100p / (125 -  p )  
 
 150p / (250 -  p )  
 
 300p / (375 -  p )  
 
 400p / (500 -  p )  
 
 500p / (625 -  p )  
怎么得出选D