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 $9 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
22 percent, what is the discount rate on Pony jeans?
(A) 9%
(B) 10%
(C) 11%
D) 12%
(E) 15%