For a commodity, the price was discounted by 10% for the first time, and the price was reduced by 5% for the second time. What is the original price of the commodity now?
一种商品，第一次打了九折，第二次又降价5%，现在该商品是原价的多少．
<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 - (1/20)</gadget>
<output>19/20 = around 0.95</output>

<gadget id="calculator">1 * (9/10) * (19/20)</gadget>
<output>171/200 = around 0.855</output>

<result>171/200 = around 0.855</result>