Two people, A and B, build a tent. It takes (1/2) hour for A to do it alone, and (1/3) hour for B to do it alone. How many hours will it take for the two to work together?
甲、乙两人搭建一顶帐篷，甲独做需(1/2)小时，乙独做需(1/3)小时，现两人合作，需多少小时．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

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

<gadget id="calculator">1 / (1/3)</gadget>
<output>3</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

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

<result>1/5 = around 0.2</result>