If the price of a commodity is increased by 20% and then reduced by 30%, what is the current price of this commodity (expressed as a percentage) from the original price?
一件商品，提价20%后又降价30%，这件商品的现价是原价的多少(用百分数表示)．
<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">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(6/5) * (7/10)</gadget>
<output>21/25 = around 0.84</output>

<result>21/25 = around 0.84</result>