Character Puzzles - General Questions

Find the missing number:

3   2   5
8   5   39
4   1   ?

Find the missing number:

9   1   18
5   4   25
2   1   ?

Find the missing number:

3   1   6
3   2   9
7   1   ?

Find the missing number:

5   4   25
3   1   6
7   2   ?

Find the missing number:

7   3   40
4   3   7
8   4   ?