Two cars, car A travels 80 kilometers per hour, and car B travels 70 kilometers per hour. Car A travels 1 hour later, and car B starts. The two cars drive opposite each other. After another 3 hours, the two cars meet. How many kilometers apart?
两辆汽车，甲车每小时行80千米，乙车每小时行70千米，甲车先1行小时后，乙车出发，两车相对而行，又经过3小时两车相遇，两地相距多少千米？
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">80 * 4</gadget>
<output>320</output>

<gadget id="calculator">70 * 3</gadget>
<output>210</output>

<gadget id="calculator">320 + 210</gadget>
<output>530</output>

<result>530</result>