A train is 290 meters long and travels 20 meters per second; B train is 250 meters long and travels 25 meters per second. The fronts of the two trains departed from opposite ends of the 900-meter-long iron bridge at the same time, and the rears of the two trains passed each other after a few seconds.
甲火车长290米，每秒行20米；乙火车长250米，每秒行25米．两火车的车头刚好同时在长900米铁桥的两端相对开出，多少秒后两车的车尾相错而过．
<gadget id="calculator">290 + 250 + 900</gadget>
<output>1_440</output>

<gadget id="calculator">20 + 25</gadget>
<output>45</output>

<gadget id="calculator">1_440 / 45</gadget>
<output>32</output>

<result>32</result>