set of suits is 320 yuan after a 20% discount. How much is this suit?
一套西服打八折后是320元，这套西服多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">320 / (4/5)</gadget>
<output>400</output>

<result>400</result>