The price of a certain commodity in two stores A and B is the same. Store A sells this product at the price, and the sales amount is 7200 yuan; Store B sells it at a 20% discount on the price, which is 15 more than Store A, and the sales volume is the same as Store A. Then how many pieces of this commodity are sold in store A?
甲、乙两商店中某商品的定价相同．甲商店按定价销售这种商品，销售额是7200元；乙商店按定价的八折销售，比甲商店多售出15件，销售额与甲商店相同．则甲商店售出多少件这种商品．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">7_200 * (4/5)</gadget>
<output>5_760</output>

<gadget id="calculator">7_200 - 5_760</gadget>
<output>1_440</output>

<gadget id="calculator">1_440 / 15 / (4/5)</gadget>
<output>120</output>

<gadget id="calculator">7_200 / 120</gadget>
<output>60</output>

<result>60</result>