For a manuscript, two people, A and B, type together. It takes 5 hours for A to complete it alone, and 8 hours for B to complete it alone. How many hours can two people work together to complete it?
一篇稿件，甲，乙两人合打．甲一个人完成要5小时，乙一个人完成要8小时，两人合打几个小时可以完成？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">(1/5) + (1/8)</gadget>
<output>13/40 = around 0.325</output>

<gadget id="calculator">1 / (13/40)</gadget>
<output>40/13 = around 3.076923</output>

<result>40/13 = around 3.076923</result>