A train of passenger cars and a train of trucks travel opposite each other. The passenger cars travel 1.4 kilometers per minute, and the trucks travel 0.85 kilometers per minute. The bus body is 600 meters long and the truck body is 1200 meters long. How many points does it take to go from two cars colliding to two cars leaving?
一列客车和一列货车相对而行，客车每分行驶1.4千米，货车每分行驶0.85千米．客车车身长600米，货车车身长1200米．在行进中从两车相遇到两车离开，需要多少分？
<gadget id="calculator">600 + 1_200</gadget>
<output>1_800</output>

<gadget id="calculator">1.4 + 0.85</gadget>
<output>2.25</output>

<gadget id="calculator">1_800 / 1_000 / 2.25</gadget>
<output>0.8</output>

<result>0.8</result>