From place A to place B, the passenger car arrives in 10 hours, and the truck travels 40 kilometers per hour from place B to place A. Now the two cars leave opposite to each other at the same time. When they meet, the truck travels 40% of the total distance. Find the distance between places A and B. distance.
从甲地到乙地，客车10小时到达，货车从乙地到甲地，每小时行40千米，现两车同时相对开出，相遇时货车行全程的40%，求甲乙两地间的距离．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

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

<gadget id="calculator">(3/5) / (1/10)</gadget>
<output>6</output>

<gadget id="calculator">6 / (2/5)</gadget>
<output>15</output>

<gadget id="calculator">40 * 15</gadget>
<output>600</output>

<result>600</result>