The distance between A and B is 300 kilometers. Two cars start from the two places at the same time and drive toward each other. After arriving at the destination, they returned immediately, and they met for the second time after 8 hours. It is known that car A travels 45 kilometers per hour, how many kilometers per hour does car B travel?
A、B两地相距300千米，两辆汽车同时从两地出发，相向而行．各自达到目的地后又立即返回，经过8小时后它们第二次相遇．已知甲车每小时行45千米，乙车每小时行多少千米？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">300 * (3/8)</gadget>
<output>225/2 = around 112.5</output>

<gadget id="calculator">(225/2) - 45</gadget>
<output>135/2 = around 67.5</output>

<result>135/2 = around 67.5</result>