The 20% discount for "Book of Fairy Tales" is 12 yuan. What is the original price?
《童话故事书》打八折是12元，原价是多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">12 / (4/5)</gadget>
<output>15</output>

<result>15</result>