The price of a coat after 30% discount is 140 yuan. The boss said: "If this coat is discounted in half, there will be neither profit nor loss." How much does this coat cost?
一件上衣打七折后的售价是140元，老板说："如果这件上衣对折就不赚也不亏"．这件上衣成本是多少元？
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">140 / (7/10)</gadget>
<output>200</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">200 * (1/2)</gadget>
<output>100</output>

<result>100</result>