Two trains, A and B, depart opposite from each other. Car A travels 76 kilometers per hour, and car B travels 68 kilometers per hour. Car B leaves only one hour after A car leaves. After another 3 hours, the two cars meet. How many kilometers is the length of the railway between the two places?
甲乙两列火车从两地相对开出．甲车每小时行76千米，乙车每小时行68千米，甲车开出一小时后，乙车才开出，再过3小时两车相遇，两地间铁路长多少千米？
<gadget id="calculator">76 + 68</gadget>
<output>144</output>

<gadget id="calculator">144 * 3</gadget>
<output>432</output>

<gadget id="calculator">432 + 76</gadget>
<output>508</output>

<result>508</result>