Two people, A and B, start from A to B at the same time, and return immediately after arriving at B. When they return, their respective speeds increase by 20%. After 1.5 hours after departure, the two vehicles meet. It is known that when B arrives at B, A There is still AB distance (1/5) from A. Ask: How many hours does it take for A car to go back and forth between A and B?
甲、乙二人同时从A地出发去B地，到达B地后立即返回，返回时各自速度均提高20%，出发后1.5小时两车相遇，已知当乙车到达B地时，甲车离A地还有AB距离的(1/5)，问：甲车在A、B间往返一次需多少小时？
<gadget id="calculator">1.5 / 2</gadget>
<output>0.75</output>

<gadget id="calculator">1.5 + 0.75</gadget>
<output>2.25</output>

<result>2.25</result>