Naughty bought 2 kilograms of bananas at a unit price of 9.9 yuan/kg. There is 17.50 yuan left, do you know how much he brought?
淘气买了2千克香蕉，单价为9.9元/千克．还剩下17.50元，你知道他带了多少钱吗？
<gadget id="calculator">9.9 * 2</gadget>
<output>19.8</output>

<gadget id="calculator">19.8 + 17.5</gadget>
<output>37.3</output>

<result>37.3</result>