The shape of an orchard is trapezoidal. Its upper base is 180 meters, its lower base is 150 meters, and its height is 60 meters. There are 900 fruit trees in this orchard. How many square meters does each fruit tree occupy on average?
一个果园的形状是梯形，它的上底是180米，下底是150米，高是60米，在这个果园共有果树900棵，平均每棵果树占地多少平方米？
<gadget id="calculator">180 + 150</gadget>
<output>330</output>

<gadget id="calculator">60 / 2 / 900</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">330 * (1/30)</gadget>
<output>11</output>

<result>11</result>