If it takes 10 minutes to saw a piece of wood into 5 sections, how many minutes will it take to saw the same piece of wood into 9 sections?
一根木料锯成5段要用10分钟，把同样的木料锯成9段需要多少分钟．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">10 / 4</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>