There are 153 peach trees in the orchard, and the number of apple trees is three times that of peach trees. How many apple trees are there?
果园里有桃树153棵，苹果树的棵数是桃树的3倍．苹果树有多少棵？
<gadget id="calculator">153 * 3</gadget>
<output>459</output>

<result>459</result>