The distance between A and B is 630 kilometers. A passenger car and a freight train leave from the two places at the same time. The passenger car travels 75 kilometers per hour, which is faster (2/3) than the freight car. How many hours later do the two cars meet?
甲乙两地相距630千米，一列客车和一列货车同时从两地相对开出，客车每小时行75千米，比货车速度快(2/3)，两车开出几小时后相遇？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 + (2/3)</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">75 / (5/3)</gadget>
<output>45</output>

<gadget id="calculator">45 + 75</gadget>
<output>120</output>

<gadget id="calculator">630 / 120</gadget>
<output>21/4 = around 5.25</output>

<result>21/4 = around 5.25</result>