udaymathapati wrote:
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. \(\frac{100p}{(125 – p)}\)
B. \(\frac{150p}{(250 – p)}\)
C. \(\frac{300p}{(375 – p)}\)
D. \(\frac{400p}{(500 – p)}\)
E. \(\frac{500p}{(625 – p)}\)
OG 2019 PS03144
Given:
1. 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.
2. 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
Asked: Which of the following expresses r in terms of p?
p% of the newspapers that the store sold were copies of newspaper A
(100-p)% of the newspapers that the store sold were copies of newspaper B
revenues from newspaper A / revenues form newspapers B = \(\frac{$p}{$1.25(100-p)} = \frac{p}{(125- 1.25p)} = \frac{r}{100-r}\)
r % of revenues come from newspaper A = \(\frac{p}{(125 -.25p)} = \frac{4p}{(500-p)} = \frac{r}{100}\)
\(r = \frac{400p}{(500-p)}\)
IMO D
_________________
Kinshook Chaturvedi
Email: kinshook.chaturvedi@gmail.com