The shape of a jujube garden is trapezoid, its upper base is 120m, lower base is 180m, and its height is 85m. If each jujube tree covers an area of 17m**2, how many jujube trees are there in this jujube garden?
一个枣园的形状是梯形，它的上底是120m，下底是180m，高是85m．如果每棵枣树占地17m**2，这个枣园共有多少棵枣树？
<gadget id="calculator">120 + 180</gadget>
<output>300</output>

<gadget id="calculator">85 / 2 / 17</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">300 * (5/2)</gadget>
<output>750</output>

<result>750</result>