The sum of the upper and lower bases of a trapezoidal land is 40 meters, which is 5 times the height. If one pear tree is planted every 5 square meters, how many pear trees can be planted in this land?
一块梯形土地的上底和下底之和是40米，是高的5倍，如果每5平方米种一棵梨树，这块地一共可以种多少棵梨树？
<gadget id="calculator">140 / 5</gadget>
<output>28</output>

<gadget id="calculator">28 / 2 / 5</gadget>
<output>14/5 = around 2.8</output>

<gadget id="calculator">140 * (14/5)</gadget>
<output>392</output>

<result>392</result>