Mom went to the market and bought 3 kilograms of tomatoes and 2 kilograms of eggs. The total cost was 19.8 yuan. If 5.4 yuan per kilogram of eggs, how much is the tomato per kilogram?
妈妈到市场买了3千克西红柿和2千克鸡蛋，一共用去19.8元，如果每千克鸡蛋5.4元，那么西红柿每千克多少钱？
<gadget id="calculator">5.4 * 2</gadget>
<output>10.8</output>

<gadget id="calculator">19.8 - 10.8</gadget>
<output>9</output>

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

<result>3</result>