The original price of a commodity is 50 yuan, and the price will be raised by 20% and then sold at a 10% discount. What is the current price?
一件商品原价50元，提价20%后再打九折出售，现价多少元．
<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">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">50 * (6/5) * (9/10)</gadget>
<output>54</output>

<result>54</result>