Bananas are 3 yuan per kilogram, apples are 2 yuan per kilogram, and each box of bananas and apples is 20 kilograms. How much is the total cost of buying a box of bananas and a box of apples?
香蕉每千克3元，苹果每千克2元，香蕉和苹果每箱都是20千克，买一箱香蕉和一箱苹果共需多少元？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">5 * 20</gadget>
<output>100</output>

<result>100</result>