A supermarket buys an electrical appliance at a cost of 400 yuan per piece, and sells it at a discounted price of 80% during the festival. In this way, the supermarket only gets 10% of the profit. What is the original price of this appliance?
一超市购进一种电器，成本每件为400元，节日期间以80%的优惠价出售，这样超市只获得10%的利润，这种电器原来的售价是多少元？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 + (1/10)</gadget>
<output>11/10 = around 1.1</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(11/10) / (4/5)</gadget>
<output>11/8 = around 1.375</output>

<gadget id="calculator">400 * (11/8)</gadget>
<output>550</output>

<result>550</result>