2023 AMC 10B Problems/Problem 2

Revision as of 17:25, 15 November 2023 by Multpi12 (talk | contribs) (Solution 2)

Problem

Carlos went to a sports store to buy running shoes. Running shoes were on sale, with prices reduced by $20\%$on every pair of shoes. Carlos also knew that he had to pay a $7.5\%$ sales tax on the discounted price. He had $$43$ dollars. What is the original (before discount) price of the most expensive shoes he could afford to buy?


$\textbf{(A) }$47\qquad\textbf{(B) }$50\qquad\textbf{(C) }$46\qquad\textbf{(D) }$48\qquad\textbf{(E) }$49$

Solution 1

Let the original price be $x$ dollars. After the discount, the price becomes $80\%x$ dollars. After tax, the price becomes $80\% \times (1+7.5\%) = 86\% x$ dollars. So, $43=86\%x$, $x=\boxed{\textbf{(B) }$50}.$

~Mintylemon66

Solution 2

We can assign a variable $c$ to represent the original cost of the running shoes. Next, we set up the equation $80\%\cdot107.5\%\cdot c=43$. We can solve this equation for $c$ and get $\boxed{\textbf{(B) }$50}$.

~vsinghminhas ~ Minor tweak:Multpi12