A farmer arranges to plant trees on a rectangular piece of land. If the number of trees planted in each row is three times the number of rows, and a total of 972 trees are planted, how many trees are there in each row?
一农夫在一块长方形的土地上安排栽种树．若每排栽种的树是排数的3倍，并且一共栽种了972棵树，问每排有多少棵树．
<gadget id="calculator">18 * 3</gadget>
<output>54</output>

<result>54</result>