It takes 6 hours for the express train to travel from A to B, and 10 hours for the slow train. Now the two trains leave from A and B at the same time. When they meet, the express train travels an extra 240 kilometers.
从甲地到乙地快车要行6小时，慢车要10小时，现在两车同时从甲乙两地相对开出，相遇时，快车多行240千米，甲乙两地相距多少千米？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

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

<gadget id="calculator">(1/6) + (1/10)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 / (4/15)</gadget>
<output>15/4 = around 3.75</output>

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

<gadget id="calculator">240 / (15/4) / (1/15)</gadget>
<output>960</output>

<result>960</result>