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 $ 8.73 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 discount rates is 22 percent, what is the discount rate on pony jeans?
Choose the correct option:
A) 9 %	B) 10 %	C) 11 %	D) 12 %	E) 13 %
<gadget id="calculator">22 / 100</gadget>
<output>11/50 = around 0.22</output>

<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<gadget id="calculator">(11/50) * 36</gadget>
<output>198/25 = around 7.92</output>

<gadget id="calculator">8.73 - (198/25)</gadget>
<output>0.81</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<gadget id="calculator">45 - 36</gadget>
<output>9</output>

<gadget id="calculator">0.81 / 9</gadget>
<output>0.09</output>

<gadget id="calculator">(11/50) - 0.09</gadget>
<output>0.13</output>

<gadget id="calculator">0.13 * 100</gadget>
<output>13</output>

<result>E</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 $ 8.73 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 discount rates is 22 percent, what is the discount rate on pony jeans?
multiply(subtract(divide(22, const_100), divide(subtract(8.73, multiply(divide(22, const_100), multiply(18, 2))), subtract(multiply(15, 3), multiply(18, 2)))), const_100)
"let x be the discount on pony jeans . then 0.22 - x is the discount on fox jeans . 3 ( 0.22 - x ) ( 15 ) + 2 x ( 18 ) = 8.73 9.9 - 45 x + 36 x = 8.73 9 x = 1.17 x = 0.13 the answer is e ."