10. (3 points) Xiaoming and Xiaohong took out the same amount of money to buy exercise books together. In the end, Xiaoming took 8 books, and Xiaohong took 12 books. As a result, Xiaohong gave Xiaoming 1.1 yuan. The unit price of each exercise book is $\qquad$ yuan.
【Solution】Solve: $1.1 \div[(12-(8+12) \div 2]$,
$$
\begin{array}{l}
=1.1 \div[12-10], \\
=1.1 \div 2, \\
=0.55 \text { (yuan); }
\end{array}
$$

Answer: The unit price of each exercise book is 0.55.
Therefore, the answer is: 0.55.