Xiao Ming and Xiao Hua go to buy the same exercise book, Xiao Ming buys 8 books, Xiao Hua buys 5 books, Xiao Ming spends 15 cents more than Xiao Hua, how much is each such exercise book.
小明和小华去买同样的练习本，小明买8本，小华买5本，小明用的钱比小华多15角钱，这种练习本每本是多少角．
<gadget id="calculator">8 - 5</gadget>
<output>3</output>

<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<result>5</result>