It cost 28.2 yuan to buy 1 schoolbag and 4 exercise books. Among them, each schoolbag is 25 yuan, and how much is each exercise book?
买1只书包和4本练习本，共花了28.2元．其中书包每只25元，练习本每本多少元？
<gadget id="calculator">28.2 - 25</gadget>
<output>3.2</output>

<gadget id="calculator">3.2 / 4</gadget>
<output>0.8</output>

<result>0.8</result>