The original price of the Encyclopedia is 500 yuan. After the 15% discount, how much is each set?
大百科全书原价500元，现在实行8.5折优惠后，每套多少元．
<gadget id="calculator">85 / 100</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">500 * (17/20)</gadget>
<output>425</output>

<result>425</result>