The original price of a book is 10 yuan, but now it is on sale for 4.8 yuan. By what percentage is the price of the book reduced?
一本书原价10元，现在4.8元出售．这本书降价了百分之几？
<gadget id="calculator">10 - 4.8</gadget>
<output>5.2</output>

<gadget id="calculator">5.2 / 10</gadget>
<output>0.52</output>

<result>0.52</result>