There are 3 rows of apple trees and 3 rows of pear trees in the orchard. There are 12 rows of apple trees and 8 rows of pear trees. How many trees are there in total?
果园里有苹果树和梨树各3行，苹果树每行12课，梨树每行8棵，这两种树一共有多少棵？
<gadget id="calculator">12 + 8</gadget>
<output>20</output>

<gadget id="calculator">20 * 3</gadget>
<output>60</output>

<result>60</result>