A businessman marked the price of a dress at 640 yuan. After being checked by industrial and commercial personnel, the price was reduced to 60 yuan and sold, and the profit was still 20%.
一个商人把一件连衣裙标价为640元，经工商人员核价，降至60元出售，仍可获利20%，如按原标价出售则一条裙子可获暴利多少元．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">60 / (6/5)</gadget>
<output>50</output>

<gadget id="calculator">640 - 50</gadget>
<output>590</output>

<result>590</result>