Answer :
Not entirely sure about question a... but b would be (lol) 27
Violas Trombones
1 3
2 6
3 9
4 12
5 15
6 18
7 21
8 24
9 27 trombones in all
Violas Trombones
1 3
2 6
3 9
4 12
5 15
6 18
7 21
8 24
9 27 trombones in all