The speed ratio of a passenger car to a truck is 5:4. The truck starts first and drives from point A to point B. When the distance from point A is 16.8 kilometers, the passenger car starts from point B to point A. When the two cars meet, the truck After traveling half of the journey, how many kilometers are there between A and B?
一辆客车与一辆货车的速度比是5：4，货车先出发从甲地开往乙地，当距离甲地16.8千米时，客车从乙地出发开往甲地，两车相遇时货车行了全程的一半，求甲、乙两地相距多少km？
<gadget id="calculator">16.8 * 5</gadget>
<output>84</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 5</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(1/2) * 4</gadget>
<output>2</output>

<gadget id="calculator">(5/2) - 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">84 / (1/2)</gadget>
<output>168</output>

<result>168</result>