Character Puzzles - General Questions

Find the missing number:

3   1   3
3   2   6
2   1   ?

Find the missing number:

2   1   2
9   8   72
8   4   ?

Find the missing number:

9   5   56
9   6   45
5   4   ?

Find the missing number:

5   1   12
9   8   34
4   1   ?

Find the missing number:

4   3   12
6   3   18
2   1   ?