Two trains, A and B, start from two places 540 kilometers apart at the same time and run toward each other. After 4 hours, the two trains meet. It is known that the distance traveled by train B per hour is that of train A (4/5). How many kilometers per hour?
甲、乙两列火车同时从相距540千米的两地出发相向而行，经过4小时后两车相遇，已知乙车每小时行的路程是甲车的(4/5)，甲车每小时行多少千米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 + (4/5)</gadget>
<output>9/5 = around 1.8</output>

<gadget id="calculator">540 / 4 / (9/5)</gadget>
<output>75</output>

<result>75</result>