train with a length of 300 meters can cross a bridge with a length of 1500 meters in 2 minutes, so what is the speed of the train in kilometers per hour?
一列长300米的火车用2分钟的时间能过长1500米的大桥，那么这列火车的速度是每小时多少千米．
<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1.8 / (1/30)</gadget>
<output>54</output>

<result>54</result>