If it takes 12 minutes to saw a piece of wood into 5 sections, how many minutes will it take to saw it into 11 sections?
把一根木头锯成5段需要12分钟，如果要锯成11段，需要多少分钟．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<gadget id="calculator">11 - 1</gadget>
<output>10</output>

<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<result>30</result>