Naughty's family of three and Xiaoxiao's family of four dined in a restaurant, and the total meal cost was 280 yuan. The two decided to share the meal expenses according to the number of people. How much should the mischievous family pay?
淘气一家三口和笑笑一家四口到餐馆用餐，餐费总共280元．两家决定按人数分摊餐费，淘气家应付多少钱？
<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">280 / 7</gadget>
<output>40</output>

<gadget id="calculator">40 * 3</gadget>
<output>120</output>

<result>120</result>