A person's passenger car speed is 40km/h, and another train coming from the opposite side passes him in exactly 6 seconds. It is known that the length of the train coming from the opposite side is 150m. Find the speed of the train coming from the opposite side.
某人乘坐的客车速度为40km/h，另一列从对面开来的列车从他身边通过正好是6s，已知对面开来的车长150m，求对面开来列车的速度．
<gadget id="calculator">90 - 40</gadget>
<output>50</output>

<result>50</result>