10. A class has 48 students, of which 24 are interested in calligraphy, and 30 are interested in music. The number of students interested in both calligraphy and music is $n$. The sum of the maximum and minimum values of $n$ is $\qquad$ .
10. 30. $\left\{\begin{array}{l}24-n \geqslant 0 \\ 30-n \geqslant 0 \quad \text { so } 6 \leqslant n \leqslant 24 . \\ 24+30-n \leqslant 48,\end{array}\right.$