A tractor plows 1.5 hectares for 2 hours in the morning and 0.8 hectares per hour for 3 hours in the afternoon. How many hectares per hour does this tractor plow on average during the day?
一台拖拉机上午2小时共耕地1.5公顷，下午耕地3小时，每小时耕0.8公顷．这一天中这台拖拉机平均每小时耕地多少公顷？
<gadget id="calculator">0.8 * 3</gadget>
<output>2.4</output>

<gadget id="calculator">2.4 + 1.5</gadget>
<output>3.9</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">3.9 / 5</gadget>
<output>0.78</output>

<result>0.78</result>