A train with a length of 125 meters passes through a tunnel with a length of 150 meters. It takes 5.5 seconds from the front of the train to the time when the whole train exits the tunnel. When it meets another freight train traveling in the opposite direction, the two cars overlap for 3 seconds. ? If the freight train is 100 meters long, what is the speed of the freight train?
一列长125公尺的火车经过一条长150公尺的隧道，由车头进入至整列火车完全驶出隧道需时5.5秒；再遇上另一列逆向行驶的运货火车，两车重迭了3秒？若运货火车长100公尺，求运货火车的车速？
<gadget id="calculator">100 + 125</gadget>
<output>225</output>

<gadget id="calculator">225 / 3</gadget>
<output>75</output>

<gadget id="calculator">125 + 150</gadget>
<output>275</output>

<gadget id="calculator">275 / 5.5</gadget>
<output>50</output>

<gadget id="calculator">75 - 50</gadget>
<output>25</output>

<result>25</result>