Xiaoying's mother opened a breakfast restaurant. There are 6 round tables and 5 square tables. Each round table can seat 3 people, and the square table can seat 4 people. How many people can have breakfast at the same time?
小颖的妈妈开了一个早餐店，共有6张圆桌和5张方桌，每张圆桌坐3人，方桌坐4人，可同时接待吃早点的客人多少人．
<gadget id="calculator">3 * 6</gadget>
<output>18</output>

<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">18 + 20</gadget>
<output>38</output>

<result>38</result>