On Children's Day, department stores increase the price of children's clothing by 50% of the purchase price, and write "big bargain, 20% discount" and the result is that each piece of children's clothing still makes a profit of 20 yuan. How much is the purchase price of this type of children's clothing?
六一儿童节，百货商场将童装按进价的50%加价后，写上"大酬宾，八折优惠"结果每件童装仍获利20元，这类童装每件进价多少元？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(3/2) * (4/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(6/5) - 1</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">20 / (1/5)</gadget>
<output>100</output>

<result>100</result>