There are 180 students in a certain school participating in computer learning this year, an increase of 20% over last year. How many people participated in computer learning last year?
某校今年参加电脑学习的有180人，比去年增加了20%，去年参加电脑学习的有多少人？
<gadget id="calculator">20 / 100</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">180 / (6/5)</gadget>
<output>150</output>

<result>150</result>