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Fri Oct 02, 2020 6:05 am

GMAT Paper Tests

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%

OA B

Solution:

At the regular prices, 3 pairs of Fox jeans and 2 pairs of Pony jeans would cost 3 x 15 + 2 x 18 = 45 + 36 = $81. Since a total of $9 is saved at the discounted prices, the cost of the same 5 pairs of jeans is now $72. Since the sum of the 2 discount rates is 22%, we can let n/100 = the discount rate of Pony jeans and (22 - n)/100 = the discount rate of Fox jeans and create the equation:

3 x 15 x (1 - (22 - n)/100) + 2 x 18 x (1 - n/100) = 72

Multiplying the equation by 100, we have:

45 x (100 - (22 - n)) + 36 x (100 - n) = 7200

45 x (78 + n) + 3600 - 36n = 7200

3510 + 45n - 36n = 3600

9n = 90

n = 10

Thus, the discount rate of Pony jeans is n/100 = 10/100 = 10%.

Answer: B