It takes 75 seconds for a train to cross a 1,200-meter bridge, and only 15 seconds for a train to pass through a roadside electric pole. How long is the train in meters?
一列火车通过一座1200米的大桥用了75秒，火车通过路旁电线杆只用15秒，火车长多少米．
<gadget id="calculator">75 - 15</gadget>
<output>60</output>

<gadget id="calculator">1_200 / 60</gadget>
<output>20</output>

<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<result>300</result>