The distance between Chengdu and Dazhou is 560 kilometers. One car travels from Dazhou to Chengdu at 80 kilometers per hour, and another car travels from Chengdu to Dazhou at 100 kilometers per hour. What is the distance between the two cars in kilometers after the two cars drive opposite each other for 3 hours?
成都达州两地相距560千米，一辆汽车从达州开往成都，每小时行80千米，另一辆汽车成都地开往达州，每小时行100千米．两车从两地相对开出3小时后，两车相距多少千米．
<gadget id="calculator">80 + 100</gadget>
<output>180</output>

<gadget id="calculator">180 * 3</gadget>
<output>540</output>

<gadget id="calculator">560 - 540</gadget>
<output>20</output>

<result>20</result>