A shop marked a dress at 580 yuan, but after being identified by anti-counterfeiting personnel, it was reduced to 60 yuan for a piece of sale, still earning 20%. So, what is the cost price of this dress?
一家商店把一条连衣裙标价为580元，经打假人员鉴别，降至60元一件出售，仍可赚20%．那么，这条连衣裙的成本价是多少元．
<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>

<result>50</result>