Grandma Wang bought a box of ice cream, 20 sticks in total, and the wholesale price is 17.2 yuan per box. If she retails at 1.5 yuan per stick, how much can she earn in total after selling this box of ice cream?
王奶奶买回来一箱雪糕，共20支，批发价每箱17.2元，如果她按每支1.5元的价格零售，卖完这箱雪糕一共能赚多少元？
<gadget id="calculator">1.5 * 20</gadget>
<output>30</output>

<gadget id="calculator">30 - 17.2</gadget>
<output>12.8</output>

<result>12.8</result>