The number of peach trees accounts for 80% of the number of pear trees, and the number of peach trees accounts for 50% of the number of apple trees. There are 100 apple trees, how many pear trees?
桃树棵数占梨树的80%，桃树棵数的50%与苹果树棵数同样多．苹果树100棵，梨树多少棵？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">100 / (1/2) / (4/5)</gadget>
<output>250</output>

<result>250</result>