A parts store is having a store-wide sale of 10% off all merchandise. An out-of-stock part can be backordered, but at a 20% fee. If a customer orders an out-of-stock part whose presale price was $40, how much will he pay? Choose the correct choice from the following choices:  A) $41.40  B) $42.00  C) $42.60  D) $43.20  E) $43.80
price = (original price - 10% decrease) + 20% increase   price = [40 * (90/100)] * (120/100) = 40 * (.90) * (1.2) = 36 * 1.2= 
<gadget id="calculator">36 * 1.2</gadget>
<output>43.2</output>
43.20   The answer is $43.20.
<result>D</result>
A parts store is having a store-wide sale of 10% off all merchandise. An out-of-stock part can be backordered, but at a 20% fee. If a customer orders an out-of-stock part whose presale price was $40, how much will he pay?