After a 30% discount on a coat, the price is 280 yuan. How much is the original price of this coat?
一件上衣打七折后，售价是280元．这件上衣的原价是多少元？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">280 / (7/10)</gadget>
<output>400</output>

<result>400</result>