Xiao Li is walking on the road next to the railway along the direction of the railway. His walking speed is 2 m/s. Given that the total length of the train is 342 meters, find the speed of the train.
小李在铁路旁边沿铁路方向的公路上散步，他散步的速度是2米/秒，这时迎面开来一列火车，从车头到车尾经过他身旁共用了18秒．已知火车全长342米，求火车的速度．
<gadget id="calculator">342 / 18</gadget>
<output>19</output>

<gadget id="calculator">19 + 2</gadget>
<output>21</output>

<result>21</result>