Fox jeans regularly sell for $15 a pair and Pony jeans regularly sell for $18 a pair. During a sale these regular unit prices are discounted at different rates so that a total of $4 is saved by purchasing 5 pairs of jeans: 3 pairs of Fox jeans and 2 pairs of Pony jeans. If the sum of the two discounts rates is 18 percent, what is the discount rate on Pony jeans?
Select the correct option:
A) 45% B) 13% C) 11% D) 12% E) 15%
You know that Fox jeans costs $15, and Pony jeans costs $18, you also know that 3 pairs of Fox jeans and 2 pairs of Pony jeans were purchased. So   3(15) = 45 - Fox   2(18) = 36 - Pony   The total discount discount is $4 and you are asked to find the percent discount of pony jeans,   so 45(18 - X)/100 + 36(X)/100 = 4 or 45*18 -45*x + 36*x =400 or - 9x = 400-45*18   or x= 410/9 =45%   =45% 45%
<result>A</result>
Fox jeans regularly sell for $15 a pair and Pony jeans regularly sell for $18 a pair. During a sale these regular unit prices are discounted at different rates so that a total of $4 is saved by purchasing 5 pairs of jeans: 3 pairs of Fox jeans and 2 pairs of Pony jeans. If the sum of the two discounts rates is 18 percent, what is the discount rate on Pony jeans?