A and B are walking towards each other on a small road next to the railway, and the speed is 1 meter per second. A train is coming towards A at a constant speed. It takes 15 seconds for the train to pass by A, and 17 seconds for the train to pass by B. What is the length of this train?
甲乙二人在铁道旁的小路上相背而行，速度都是每秒行1米．一列火车匀速向甲迎面驶来，列车在甲身边开过用了15秒钟，而后在乙身边通过用了17秒钟．这列火车车长是多少米．
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">15 * (1/15)</gadget>
<output>1</output>

<gadget id="calculator">1 / 17</gadget>
<output>1/17 = around 0.058824</output>

<gadget id="calculator">17 * (1/17)</gadget>
<output>1</output>

<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">(1/15) - (1/17)</gadget>
<output>2/255 = around 0.007843</output>

<gadget id="calculator">2 / (2/255)</gadget>
<output>255</output>

<result>255</result>