The selling price of a book after the price reduction (1/10) is 36 yuan, what is the original price?
一本书降价(1/10)后的售价是36元，原价是多少元．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 - (1/10)</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">36 / (9/10)</gadget>
<output>40</output>

<result>40</result>