The speed ratio of the passenger car and the freight car is 4:3. The passenger car and the freight car depart from A and B respectively at the same time and drive toward each other. After 3 hours of meeting, how many hours will it take for the passenger car to get from A to B?
客车和货车的速度比是4：3，客车和货车分别从甲、乙两地同时出发，相向而行，经过3小时相遇，客车从甲地到达乙地一共要用多少小时．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">(1/3) * (4/7)</gadget>
<output>4/21 = around 0.190476</output>

<gadget id="calculator">1 / (4/21)</gadget>
<output>21/4 = around 5.25</output>

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