Mom took 50 yuan to the supermarket to buy vegetables, including 17.45 yuan for fish and meat, and 12.55 yuan for vegetables. How much money is left in the end?
妈妈带了50元去超市买菜，其中买鱼和肉共花了17.45元，买蔬菜花了12.55元，最后还剩下多少元？
<gadget id="calculator">17.45 + 12.55</gadget>
<output>30</output>

<gadget id="calculator">50 - 30</gadget>
<output>20</output>

<result>20</result>