There are 150 apple trees in the orchard, 20 more pear trees than apple trees, and twice as many orange trees as the total number of apple and pear trees. How many orange trees are there?
果园有苹果树150棵，梨树比苹果树多20棵，橘子树的棵数是苹果树和梨树总棵数的2倍．橘子树是多少棵？
<gadget id="calculator">150 + 20 + 150</gadget>
<output>320</output>

<gadget id="calculator">320 * 2</gadget>
<output>640</output>

<result>640</result>