Two engineering teams, A and B, work together to build a road. It takes 8 days for A and B to repair it alone, and 10 days for A to repair it alone.
甲、乙两个工程队共修一条路，甲工程队单独修需要8天，甲工程队单独修需要10天，乙先修1天，剩下的由甲乙共同工作还需要几天修完？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/8) + (1/10)</gadget>
<output>9/40 = around 0.225</output>

<gadget id="calculator">(9/10) / (9/40)</gadget>
<output>4</output>

<result>4</result>