The distance between A and B is 90 kilometers. Both A and B start from city A to city B by bicycle at the same time. A’s speed is 3 kilometers slower than that of B per hour. B arrives at city B and returns immediately. Meet A at a distance of 15 kilometers from City B. How many kilometers does A travel per hour?
A、B两地相距90千米，甲、乙两人都骑自行车从A城同时出发往B城，甲的速度每小时比乙慢3千米，乙到达B城立即返回．在距B城15千米处与甲相遇．甲每小时行多少千米？
<gadget id="calculator">65 / 10</gadget>
<output>13/2 = around 6.5</output>

<result>13/2 = around 6.5</result>