The number of students graduating from Hope Primary School this year is 10% more than that of last year. The number of graduates this year is 20 more than last year. How many graduates were there last year?
希望小学今年毕业的学生人数比去年毕业的多10%，今年毕业生人数比去年多了20人，去年有多少名毕业生．
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">20 / (1/10)</gadget>
<output>200</output>

<result>200</result>