Each worker in the timber factory can produce 4 tables or 7 chairs per day. One table and one chair are a set. There are 55 workers. How many sets can be produced at most per day?
木材厂的工人每人每天可以生产4张桌子或7把椅子，一张桌子和一把椅子为一套，现有工人55名，每天最多能生产多少套？
<gadget id="calculator">7 + 4</gadget>
<output>11</output>

<gadget id="calculator">55 / 11</gadget>
<output>5</output>

<gadget id="calculator">5 * 7</gadget>
<output>35</output>

<gadget id="calculator">4 * 35</gadget>
<output>140</output>

<result>140</result>