The distance between A and B is 560 kilometers. Two cars drive from the two places at the same time. After 4 hours, the two cars meet. The express train travels 80 kilometers per hour. How many kilometers per hour does the slow train travel?
甲乙两地相距560千米，两车从两地同时相对开出，4小时后两车相遇，快车每小时行80千米，慢车每小时行多少千米？
<gadget id="calculator">560 / 4</gadget>
<output>140</output>

<gadget id="calculator">140 - 80</gadget>
<output>60</output>

<result>60</result>