It takes 6 hours for an express train to go from place A to place B, and 8 hours for a slow train to go from place B to place A. When two trains depart from places A and B at the same time, how many hours will they meet?
一辆快车从甲地开往乙地需要6小时，一辆慢车从乙地开往甲地需要8小时，两辆火车同时从甲、乙两地相对开出，多少小时相遇．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

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

<gadget id="calculator">(1/6) + (1/8)</gadget>
<output>7/24 = around 0.291667</output>

<gadget id="calculator">1 / (7/24)</gadget>
<output>24/7 = around 3.428571</output>

<result>24/7 = around 3.428571</result>