A pan can only bake 2 cakes at a time, and it takes 3 minutes to bake one side, how many minutes does it take to bake 5 cakes.
一个平底锅，每次最多只能烙2张饼，烙一面需要3分钟，烙5张饼需要多少分钟．
<gadget id="calculator">2 * 3</gadget>
<output>6</output>

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

<gadget id="calculator">6 + 9</gadget>
<output>15</output>

<result>15</result>