Bake cakes on the baking tray, only 2 sheets can be placed at a time, both sides of the cake must be baked, it takes 5 minutes for each side to be baked, how many minutes is the minimum time required to bake 5 sheets of cakes.
在烤盘上烤饼，每次只能放2张，饼的两面都要烤，每烤完一面需要5分钟，烤5张饼最少需要多少分钟．
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">10 + 15</gadget>
<output>25</output>

<result>25</result>