To build a 600-meter-long road, Team A will complete the repair in 8 days alone, and Team B will complete the repair in 10 days alone. How many days did the two teams work together to complete it (9/10).
修一段600米长的路，甲队单独修8天完成，乙队单独修10天完成．两队合修多少天完成它的(9/10)．
<gadget id="calculator">9 / 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 / 10</gadget>
<output>1/10 = around 0.1</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>