New fashion clothing stores sell seasonally discounted clothing. A kind of clothing is sold at 30% off the original price, which is 120 yuan cheaper than the original price. How much is the original price of this dress?
新时尚服装店里服装换季打折出售．一种服装按照原价的七折出售，这样就比原价便宜了120元．这种服装原价是多少元？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">120 / (3/10)</gadget>
<output>400</output>

<result>400</result>