book is priced at 75 yuan. If it is sold at a 20% discount, how much is the current price?
一本书定价75元，如果打八折出售，现价多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">75 * (4/5)</gadget>
<output>60</output>

<result>60</result>