The two trains meet, the speed of the "Long March" train is 60 kilometers per hour, and the speed of the "Dongfeng" train is 90 kilometers per hour. Tao Tao was on the "Dongfeng" train, and he found that it took a total of 6 seconds for the "Long March" train to pass by the window. After a while, he confidently calculated how long the "Long March" train was. Do you know how long the "Long March" train is?
两列列车相遇了，"长征号"列车的速度是每小时60千米，"东风号"列车的速度是每小时90千米．陶陶在"东风号"列车上，他发现"长征号"列车从窗前开过的时间总共花了6秒钟，过了一会儿，他就自信地算出了"长征号"列车有多长了．你知道"长征号"列车有多长吗？
<gadget id="calculator">60 + 90</gadget>
<output>150</output>

<gadget id="calculator">6 / 3_600</gadget>
<output>1/600 = around 0.001667</output>

<gadget id="calculator">150 * (1/600) * 1_000</gadget>
<output>250</output>

<result>250</result>