After the price of a schoolbag is reduced (1/5), the price is 80 yuan. What is the original price of this schoolbag?
一个书包降价(1/5)后，售价为80元，这个书包原价是多少元？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">80 / (4/5)</gadget>
<output>100</output>

<result>100</result>