It takes 16 days for A to repair a road alone, and 24 days for B to repair it alone. If B repairs it for 9 days first, and then A and B jointly repair it, how many days will it take?
修一条路，甲单独修需16天，乙单独修需24天，如果乙先修了9天，然后甲、乙二人合修，还要几天？
<gadget id="calculator">1 / 24</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">(1/24) * 9</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 - (3/8)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">1 / 16</gadget>
<output>1/16 = around 0.0625</output>

<gadget id="calculator">(1/16) + (1/24)</gadget>
<output>5/48 = around 0.104167</output>

<gadget id="calculator">(5/8) / (5/48)</gadget>
<output>6</output>

<result>6</result>