Mom wants to bake 11 cakes. She can only bake two sheets at a time. Both sides must be baked for 3 minutes on each side. How long will it take at least to bake these 11 cakes?
妈妈要烙11饼，每次只能烙两张，两面都要烙，每面3分钟，至少需要多少分钟才能烙熟这11张饼．
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">3 * 2 * 4</gadget>
<output>24</output>

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

<gadget id="calculator">24 + 9</gadget>
<output>33</output>

<result>33</result>