A road can be completed in 10 days alone, and B can be completed in 15 days alone. Now they work together in 5 days. How much of this road is left?
一条路，甲单独修10天完成，乙单独修15天完成，现在合做5天，还剩下这条路的多少．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/10) + (1/15)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) * 5</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 - (5/6)</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>