Xiaoli mail-ordered 3 copies of the same book from the publishing house, and the total price including postage was 37.5 yuan. If the postage for 3 books is $6, how much is each book?
小丽从出版社邮购了3本同样的书，包括邮费总价是37.5元．如果3本书的邮费是6元，那么每本书多少元？
<gadget id="calculator">37.5 - 6</gadget>
<output>31.5</output>

<gadget id="calculator">31.5 / 3</gadget>
<output>10.5</output>

<result>10.5</result>