Two trains depart from two stations at the same time, A travels 45 kilometers per hour, B travels 54 kilometers per hour, and they meet after 3.5 hours. How long is the railway between the two stations?
两列火车从两个车站同时相对开出，甲每小时行45千米，乙每小时行54千米，经过3.5小时相遇．两个车站之间的铁路长多少千米？
<gadget id="calculator">45 + 54</gadget>
<output>99</output>

<gadget id="calculator">99 * 3.5</gadget>
<output>346.5</output>

<result>346.5</result>