A passenger car travels from Dehua to Quanzhou. It travels an average of 45 kilometers per hour in the first 2 hours and 60 kilometers in the next hour. Find the average speed of this bus from Dehua to Quanzhou.
一辆客车从德化到泉州，前2小时，平均每小时行45千米，后1小时行60千米，求这辆汽车从德化到泉州的平均速度．
<gadget id="calculator">45 * 2</gadget>
<output>90</output>

<gadget id="calculator">60 * 1</gadget>
<output>60</output>

<gadget id="calculator">90 + 60</gadget>
<output>150</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">150 / 3</gadget>
<output>50</output>

<result>50</result>