A certain product is increased by 15% on the basis of the original price, and the sales volume has dropped significantly, so the price has been reduced by 15%. The selling price at this time is the original price.
某商品在原价的基础上提高15%，销售量明显下降，于是又降价15%，此时的售价是原价的多少．
<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 + (3/20)</gadget>
<output>23/20 = around 1.15</output>

<gadget id="calculator">1 - (3/20)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">(17/20) / 1</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1 * (23/20) * (17/20)</gadget>
<output>391/400 = around 0.9775</output>

<result>391/400 = around 0.9775</result>