The price of an apple is 3.80 yuan per kilogram. Xiaoming’s mother bought 5 kilograms. She paid 50 yuan. How much should she get back?
苹果每千克售价3.80元，小明的妈妈买了5千克，她付出50元，应找回多少元？
<gadget id="calculator">3.8 * 5</gadget>
<output>19</output>

<gadget id="calculator">50 - 19</gadget>
<output>31</output>

<result>31</result>