According to the given information we can classify the working of instructors as :-
Music Instructor works from 12-4 pm on - Monday, Thursday and Sunday.
Dance Instructor works from 10 am-2 pm on - Tuesday, Wednesday, Thursday and Sunday
Painting Instructor works from -9 am - 12 noon on - Tuesday, Thursday and Friday
2 - 4 pm on - Wednesday, Saturday and Sunday
After this classification it is clear that Tuesday and Thursday are the days of the week the dance and painting sessions are simultaneously held.