It takes 10 days for A to build a road alone, and 8 days for B to do it alone. After how many days, B will repair half of the road more than A?
修一条路，甲单独做要10天，乙单独做要8天，多少天后乙比甲多修这条路的一半？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</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>1/40 = around 0.025</output>

<gadget id="calculator">(1/2) / (1/40)</gadget>
<output>20</output>

<result>20</result>