A railway bridge is 1,200 meters long, and it takes 75 seconds for a train to cross the bridge; it only takes 15 seconds for a train to cross the electric pole beside the road, so what is the total length of the train in meters?
一座铁路桥全长1200米，一列火车开过大桥需花费75秒；火车开过路旁电杆，只要花费15秒，那么火车全长是多少米．
<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>