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%

Let us assume the discount rate of Fox jeans is F and Pony jeans is P. We have to find out the value of P.

Now given that F + P = 22 (Given that the sum of the discount rates is 22). This is one equation. We need one more equation to solve for P.

Now we are given that 3 pairs of Fox jeans and 2 pairs of Pony jeans if purchased at discount price will save $9. So sum of the individual discounts of Fox jeans and Pony jeans will add to $9.

For 3 pairs of Fox jeans the discount = 3 x $15 x F/100 (F percent is actually F/100).
For 2 pairs of Pony jeans the discount = 2 x $18 x P/100

So 45F/100 + 36P/100 = 9. If it is simplified, the equation becomes

45F + 36P = 900 which again simplifies to
5F + 4P = 100

Now we have 2 equations F + P = 22 and 5F + 4P = 100

Solving this we get P = 10.

The answer is (B).

Nice job, Harish!