It takes 3 hours for A to finish typing alone, and 5 hours for B to finish typing alone. How many hours can A and B finish half of the material?
一份材料，甲单独打完要3小时，乙单独打完要5小时，甲、乙两人合打多少小时能打完这份材料的一半？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/3) + (1/5)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">(1/2) / (8/15)</gadget>
<output>15/16 = around 0.9375</output>

<result>15/16 = around 0.9375</result>