Xiao Ming went to the stationery store and bought 3 pens and 5 exercise books, and the total cost was 35.5 yuan. It is known that each pen is 10.5 yuan, how much is each exercise book?
小明到文具店买了3支钢笔和5个练习本，共用了35.5元，已知每支钢笔10.5元，每个练习本多少元？
<gadget id="calculator">10.5 * 3</gadget>
<output>31.5</output>

<gadget id="calculator">35.5 - 31.5</gadget>
<output>4</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>