train is 640 meters long and it takes 40 seconds to pass a big tree on the side of the road. If it passes a bridge 800 meters long at the same speed, how many seconds will it take?
一列火车长640米，从路旁的一棵大树旁通过，需要40秒钟，如果以同样的速度通过一座长800米的大桥，需要多少秒？
<gadget id="calculator">640 + 800</gadget>
<output>1_440</output>

<gadget id="calculator">640 / 40</gadget>
<output>16</output>

<gadget id="calculator">1_440 / 16</gadget>
<output>90</output>

<result>90</result>