It takes 6 hours for a passenger car to go from point A to point B, and it takes 4 hours for a truck to go from point B to point A. The two cars depart from the two places at the same time, and how many hours later will they meet?
一辆客车从A地到B地需要6小时，一辆货车从B地到A地需要4小时，两车从两地同时相对开出，几小时后相遇？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/6) + (1/4)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">1 / (5/12)</gadget>
<output>12/5 = around 2.4</output>

<result>12/5 = around 2.4</result>