There is a set of "Children's Encyclopedia" in the bookstore. The original price is 125 yuan, and it is now on sale at a 20% discount. How much cheaper can I buy a set?
书店有一套《少儿百科》，原价125元，现八折出售，买一套可以便宜多少元？
<gadget id="calculator">125 * 0.2</gadget>
<output>25</output>

<result>25</result>