A piece of clothing was sold at the original price on the first day, but no one came to buy it; the price was reduced by 20% on the second day, but no one came to buy it; It is known that the selling price on the third day is exactly 65% of the original price. How much is the original price of this dress?
一件衣服，第一天按原价出售，没人来买；第二天降价20%，仍没人来买；第三天再降价60元钱，终于售出．已知第三天售价恰好是原价的65%，这件衣服的原价是多少元钱？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">65 / 100</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">1 - (1/5) - (13/20)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">60 / (3/20)</gadget>
<output>400</output>

<result>400</result>