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 $5 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?  Choose the correct option:
A) 9%	B) 10%	C) 34.4%	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 $5 and you are asked to find the percent discount of pony jeans,   so 45(18 - X)/100 + 36(X)/100 = 5 or 45*18 -45*x + 36*x =5*100 or 9x = -5*100 +45*18= 
<gadget id="calculator">-5*100 +45*18</gadget>
<output>310</output>
310/9=34.4   34.4%
<result>C</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 $5 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?