A set of clothes sells for 170 yuan, earning 70%, so how much is the purchase price of this suit.
一套衣服卖170元，赚了70%，那么这套衣服的进价是多少元．
<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 + (7/10)</gadget>
<output>17/10 = around 1.7</output>

<gadget id="calculator">170 / (17/10)</gadget>
<output>100</output>

<result>100</result>