On a ring road, two cars, A and B, leave opposite directions at the same station. Car A travels 40 kilometers per hour, and car B travels 38 kilometers per hour. Car B leaves after 1.5 hours. 2.5 hours, two cars meet on the way, how long is this ring road?
在一条环行公路上，甲乙两车在同一车站先后相背开出，甲车每小时行40千米，乙车每小时行38千米，甲车开出1.5小时后，乙车开出，经过2.5小时，两车在途中相遇，这条环行公路有多长？
<gadget id="calculator">1.5 + 2.5</gadget>
<output>4</output>

<gadget id="calculator">40 * 4</gadget>
<output>160</output>

<gadget id="calculator">38 * 2.5</gadget>
<output>95</output>

<gadget id="calculator">160 + 95</gadget>
<output>255</output>

<result>255</result>