Flour costs 2.5 yuan per kilogram, and Aunt Wang buys 15.28 kilograms of this kind of flour. Aunt Wang paid the salesperson 50 yuan, how much should I get back?
面粉每千克2.5元，王阿姨买15.28千克这种面粉．王阿姨付给售货员50元，应找回多少元？
<gadget id="calculator">2.5 * 15.28</gadget>
<output>38.2</output>

<gadget id="calculator">50 - 38.2</gadget>
<output>11.8</output>

<result>11.8</result>