The highway from Beijing to Changchun is 1020km long. A passenger car departs from Changchun Station to Beijing, and a truck departs from Beijing to Changchun at the same time. The two vehicles meet on the way after 6 hours. The passenger car travels 90 km per hour, how many kilometers per hour does the truck travel?
北京到长春的公路长1020km，一辆客车从长春站出发开往北京，一辆货车同时从北京开往长春，两车经过6小时后在途中相遇．客车每小时行90km，货车每小时行多少千米？
<gadget id="calculator">1_020 / 6</gadget>
<output>170</output>

<gadget id="calculator">170 - 90</gadget>
<output>80</output>

<result>80</result>