A car drives from point A to point B. It travels 56.4 kilometers in the first 2.5 hours and an average of 67.8 kilometers per hour in the last 1.5 hours. Find the average speed of the car from point A to point B.
一辆车从A地开往B地，前2.5小时行驶56.4千米，后1.5小时平均每小时行驶67.8千米．求这辆车从A地到B地的平均速度．
<gadget id="calculator">1.5 * 67.8</gadget>
<output>101.7</output>

<gadget id="calculator">56.4 + 101.7</gadget>
<output>158.1</output>

<gadget id="calculator">2.5 + 1.5</gadget>
<output>4</output>

<gadget id="calculator">158.1 / 4</gadget>
<output>39.525</output>

<result>39.525</result>