Cars A and B depart from A to B at the same time. Car A arrives at B and returns immediately. It takes 5 hours from departure to when the two cars meet. If A and B start from A and B at the same time Driving towards each other, the distance between the two cars is 180 km after 1 hour, find the sum of the speeds of the two cars.
甲、乙两车同时从A地出发开往B地，甲车到达B地并立即返回，从出发到两车相遇共用了5小时，如果甲、乙两车分别从A、B两地同时出发相向而行，1小时后两车相距180千米，求两车的速度和．
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) - 1</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">180 / (3/2)</gadget>
<output>120</output>

<result>120</result>