It takes 75 seconds for a train to cross a bridge with a length of 1200 meters, and it only takes 15 seconds for a train to cross a power pole beside the road. How long is the train in meters?
一列火车开过一座长1200米的大桥，需要75秒钟，火车开过路旁的电线杆只需15秒钟，求火车长多少米？
<gadget id="calculator">75 / 15</gadget>
<output>5</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">1_200 / 4</gadget>
<output>300</output>

<result>300</result>