A store puts a 20% increase on the purchase price of a certain electrical appliance as the price. Then there was an advertisement for a 10% discount (that is, 90% of the list price) discount. The price of the electrical appliance that Xiao Ming saw on the promotional advertisement is 2,700 yuan. How much is the purchase price of this electrical appliance?
一家商店将某种电器按进价加价20%作为标价．随后又打出九折(即按标价的90%)优惠大促销的广告．小明在优惠大促销的广告单上看到的该电器的价格是2700元，这种电器进价是多少元？
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">2_700 / (9/10) / (6/5)</gadget>
<output>2_500</output>

<result>2_500</result>