80 students, 15 M, 15 P, 30 C. All 3 = none. 10 M&C, 5 M&P, 8 C&P only. Find number of students doing at least one subject.

This problem involves set theory and probability. The image quality is low, but I've deciphered the problem statement as follows:

In a class, there are 80 students.
15 are doing Math (M).
15 are doing Physics (P).
30 are doing Chemistry (C).
The number of students doing all three subjects equals the number of those not doing any subject.
10 students do Math and Chemistry.
5 students do Math and Physics.
8 students do only Chemistry and Physics.

Let's denote:
$N = 80$ (Total students)
$