A piece of land has (9/10) hectares, and 3 tractors can be used to plow it in (1/2) hour. How many hectares of land is plowed by each tractor per hour on average?
一块地有(9/10)公顷，用3台拖拉机耕，(1/2)小时可以耕完，平均每台拖拉机每小时耕地多少公顷？
<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

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

<gadget id="calculator">(9/10) / (1/2) / 3</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>