A school planted 20% more trees this year than last year, and 5 hectares less last year than this year. How many hectares were planted last year?
某校今年植树比去年多20%，去年比今年少5公顷，去年植树多少公顷？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">5 / (1/5)</gadget>
<output>25</output>

<result>25</result>