The price of a commodity after a 20% discount is 72 yuan. What is the original price of this commodity?
一种商品打八折后的售价是72元，这种商品的原价是多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">72 / (4/5)</gadget>
<output>90</output>

<result>90</result>