Two cleaning vehicles, A and B, perform the task of cleaning the road between the east and west cities. It takes 10 hours for car A to clean alone, and 15 hours for car B to clean alone. The two cars drive from the east and west at the same time. When they meet, car A cleans 12 kilometers more than car B. How many kilometers are the distance between the east and west cities? ?
甲、乙两辆清洁车执行东、西城间的公路清扫任务．甲车单独清扫需要10小时，乙车单独清扫需要15小时，两车同时从东、西城相向开出，相遇时甲车比乙车多清扫12千米，问东、西两城相距多少千米？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/10) + (1/15)</gadget>
<output>1/6 = around 0.166667</output>

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

<gadget id="calculator">(1/10) * 6</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(1/15) * 6</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">12 / (1/5)</gadget>
<output>60</output>

<result>60</result>