If it takes 5 minutes to saw a piece of wood into 3 sections, how long will it take to saw the same piece of wood into 9 sections at the same speed?
如果把一根木料锯成3段需要5分钟，那么用同样的速度，把这根木料锯成9段，需要多长时间？
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<gadget id="calculator">(5/2) * 8</gadget>
<output>20</output>

<result>20</result>