Two passenger and freight trains depart from A and B respectively at the same time, and travel towards each other. After 6 hours, the two vehicles meet, and the passenger car continues to drive for 4 hours to arrive at B. How many more hours does the train have to travel to reach A?
客、货两车分别从甲、乙两地同时出发，相向而行，经过6小时两车相遇后，客车继续行驶4小时到达乙地，火车还需再行驶几小时才能到达甲地？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/6) - (1/10)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">1 / (1/15)</gadget>
<output>15</output>

<gadget id="calculator">15 - 6</gadget>
<output>9</output>

<result>9</result>