There are 120 peach trees in the orchard, which are 1/5 more than apricot trees. How many apricot trees are there? What is the correct formula below
果园里有桃树120棵，比杏树多(1/5)，求杏树有多少棵．下面正确的算式是多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">120 / (6/5)</gadget>
<output>100</output>

<result>100</result>