A certain brand of clothing is priced at 420 yuan after a price reduction (2/7) for promotional purposes. How much is the original price of this dress?
某品牌服装为了促销，降价(2/7)后，售价是420元．这种服装原价多少元？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">420 / (5/7)</gadget>
<output>588</output>

<result>588</result>