Mom took 20 yuan to buy 3 kilograms of tomatoes, and there is 3.2 yuan left. How much is a kilogram of tomatoes?
妈妈拿了20元钱买了3千克西红柿，还剩3.2元，每千克西红柿多少元？
<gadget id="calculator">20 - 3.2</gadget>
<output>16.8</output>

<gadget id="calculator">16.8 / 3</gadget>
<output>5.6</output>

<result>5.6</result>