A school purchased plants, 3 trees and 7 potted flowers, and paid 1140.8 in total. It is known that the price of one potted flower is equivalent to the money of 4 trees. How much is a tree?
某校采购植物，3棵树和7盆花，共付1140.8，已知一盆花的钱相当于4棵树的钱，一棵树多少元？
<gadget id="calculator">4 * 7</gadget>
<output>28</output>

<gadget id="calculator">3 + 28</gadget>
<output>31</output>

<gadget id="calculator">1_140.8 / 31</gadget>
<output>36.8</output>

<result>36.8</result>