The grain output of a certain county last year was 28,000 tons, an increase of 20% over the previous year. How many tons of grain was produced in the previous year?
某县去年粮食产量为2.8万吨，去年比前年增产两成．前年粮食产量是多少万吨．
<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">2.8 / (6/5)</gadget>
<output>2.333333</output>

<result>2.333333</result>