Ning Ning bought 3 identical hats. After paying 50 yuan to the salesperson, there was still 13 yuan left unpaid. How much is each hat?
宁宁买了3顶相同的帽子，付给售货员50元后，还差13元没有付，每顶帽子多少元？
<gadget id="calculator">50 + 13</gadget>
<output>63</output>

<gadget id="calculator">63 / 3</gadget>
<output>21</output>

<result>21</result>