A color TV set is sold for 2100 yuan after a 30% discount. What is the original price of this TV set?
一台彩色电视机打七折后卖2100元，这台电视机原价是多少元．
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">2_100 / (7/10)</gadget>
<output>3_000</output>

<result>3_000</result>