There is a road between A and B. It takes 60 minutes for car A to go from A to B, and it takes 120 minutes for car B to go from B to A. If two cars A and B depart from A and B respectively at the same time, how many minutes will they meet after departure?
A、B两地间有一条公路．甲车从A驶到B，需60分钟；乙车从B驶到A，需120分钟．若甲、乙两车分别从A、B两地同时出发，则在出发后多少分钟相遇．
<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">1 / 120</gadget>
<output>1/120 = around 0.008333</output>

<gadget id="calculator">(1/60) + (1/120)</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">1 / (1/40)</gadget>
<output>40</output>

<result>40</result>