Cars A and B drive in opposite directions from two places. Car A takes 20 hours to complete the journey, and Car B takes 3/2 of the time to complete the journey. How many hours before the two cars meet?
甲、乙两车从两地相向开出，甲车行完全程用20小时，乙车行完全程所用的时间是甲车的(3/2)．两车出发多少小时后相遇？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">20 * (3/2)</gadget>
<output>30</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/20) + (1/30)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / (1/12)</gadget>
<output>12</output>

<result>12</result>