In a forest park, there is a 45-kilometer-long sloping road. There are two horse-drawn carriages carrying tourists at both ends of the sloping road at the same time. The horse-drawn carriage travels 5 kilometers per hour, and the charge is 5.5 yuan. The fare has been paid when the two cars depart. When the two cars meet on the way, the two cars exchange passengers and return to the original place immediately. Q: How should the driver of two vehicles settle the fare?
某森林公园里，有一段长45千米的坡路，有两辆马车在坡路的两端各载游客同时出发，相向而行，下坡马车每小时行10千米，收费4元；上坡马车每小时行5千米，收费5.5元．车费在两辆车出发时已经付清，当两辆车在途中相遇时，这两辆车互相交换乘客后立即返回原地．问：两辆车的驾车人应该怎样结算车费？
<gadget id="calculator">10 + 5</gadget>
<output>15</output>

<gadget id="calculator">45 / 15 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">10 * (3/10) * 4</gadget>
<output>12</output>

<gadget id="calculator">45 / 15 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">10 * (3/5) * 5.5</gadget>
<output>33</output>

<gadget id="calculator">45 / 10</gadget>
<output>9/2 = around 4.5</output>

<gadget id="calculator">(9/2) * 4</gadget>
<output>18</output>

<gadget id="calculator">33 - 18</gadget>
<output>15</output>

<gadget id="calculator">12 + 15</gadget>
<output>27</output>

<result>27</result>