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At a certain store, the retail price of a coat was \(p\) percent less than its list price. If the sale price of the coat was \(r\) percent less than its retail price, then the sale price of the coat was what percent of its list price?
(1) \(p - r + \frac{pr}{100} = 10\)
(2) \(p + r - \frac{pr}{100} = 40\)
Assume that -
- the retail price of the coat = \(R\)
- the list price of the coat = \(L\)
- the sale price of the coat = \(S\)
"...At a certain store, the retail price of a coat was \(p\) percent less than its list price..."\(R = L(1-\frac{p}{100})\)
"...If the sale price of the coat was \(r\) percent less than its retail price..."\(S = R(1-\frac{r}{100}) = L(1-\frac{p}{100})(1-\frac{r}{100})\)
Question:
...then the sale price of the coat was what percent of its list price...\(\frac{S}{L} * 100\) = ?
Let's simplify this my multiplying \(\frac{100}{L}\) on both sides of the equation-
\(S = L(1-\frac{p}{100})(1-\frac{r}{100})\)
\(\frac{S}{L} * 100 = 100(1-\frac{p}{100})(1-\frac{r}{100})\)
\(\frac{S}{L} * 100 = 100(1-\frac{p}{100})(1-\frac{r}{100})\)
\(\frac{S}{L} * 100 = 100(1 - \frac{r}{100} - \frac{p}{100} + \frac{pr}{100^2})\)
\(\frac{S}{L} * 100 = 100 - r - p + \frac{pr}{100}\)
\(\frac{S}{L} * 100 = 100 - (r + p - \frac{pr}{100})\)
Let's start with Statement 2
Statement 2(2) \(p + r - \frac{pr}{100} = 40\)We are given the value of \(r + p - \frac{pr}{100}\), hence that's sufficient to answer the question.
Eliminate A, C, and E.
Statement 1(1) \(p - r + \frac{pr}{100} = 10\)Not sufficient, as we can multiple possible values of \(p\) and \(r\) satisfying the equation.
Option B