After a certain organization streamlined the organization, there were 120 employees, and 30 people were reduced. What percentage was the reduction? what is the correct formula
某机关精简机构后有职工120人，精简了30人，精减了百分之几？正确的算式是多少
<gadget id="calculator">120 + 30</gadget>
<output>150</output>

<gadget id="calculator">30 / 150</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>