10 yuan for 3 kilograms of apples and 7 yuan for 3 kilograms of pears. Mom bought 6 kilograms of apples and 9 kilograms of pears in the fruit supermarket. How much should I pay?
每3千克苹果10元，3千克梨7元，妈妈在水果超市买了6千克苹果和9千克梨，应付多少钱？
<gadget id="calculator">6 / 3</gadget>
<output>2</output>

<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">9 / 3</gadget>
<output>3</output>

<gadget id="calculator">3 * 7</gadget>
<output>21</output>

<gadget id="calculator">20 + 21</gadget>
<output>41</output>

<result>41</result>