Teacher Wu bought a printer and 8 packs of the same printing paper at a stationery store, and the total cost was 700 yuan. The price of the printer is 580 yuan, how much is each pack of printing paper?
吴老师在文具商店买了一台打印机和8包同样的打印纸，一共用去700元．打印机的价格是580元，每包打印纸多少元？
<gadget id="calculator">700 - 580</gadget>
<output>120</output>

<gadget id="calculator">120 / 8</gadget>
<output>15</output>

<result>15</result>