The distance between A and B is 5 kilometers. Two trains depart from two places at the same time and run in opposite directions. The passenger train travels 50 kilometers per hour, and the freight train travels 48 kilometers per hour. After 2.5 hours, how many kilometers are the distance between the two trains?
甲乙两地相距5千米．两列火车同时从两地开出背向而行，客车每小时行50千米，货车每小时行48千米，经过2.5小时，两车相距多少千米？
<gadget id="calculator">50 + 48</gadget>
<output>98</output>

<gadget id="calculator">98 * 2.5</gadget>
<output>245</output>

<gadget id="calculator">245 + 5</gadget>
<output>250</output>

<result>250</result>