The number of peach trees in the orchard is 4 times that of apricot trees, and the number of apple trees is 3.5 times that of apricot trees. It is known that there are 150 more peach trees than apple trees, how many apricot trees are there?
果园里桃树的棵数是杏树的4倍，苹果树的棵数是杏树的3.5倍．已知桃树比苹果树多150棵，杏树有多少棵？
<gadget id="calculator">4 - 3.5</gadget>
<output>0.5</output>

<gadget id="calculator">150 / 0.5</gadget>
<output>300</output>

<result>300</result>