There are 80 apple trees planted in the orchard, which is 20 more than three times the number of pear trees planted. How many pear trees are planted? (column equation solution)
果园里种了80棵苹果树，比种的梨树的3倍多20棵，种了梨树多少棵？(列方程解答)
<gadget id="calculator">80 - 20</gadget>
<output>60</output>

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

<result>20</result>