Puzzles - Logical puzzles

37.
Answer
:
P
Explanation
:
Working in rows, add the left and right hand numbers together, and put the letter with the reverse alphabetical value of this sum in the central box.

38.
Answer
:
B
Explanation
:
[NIL]

39.
Answer
:
B
Explanation
:
In each row, the left hand grid contains one line of black dots, the central one contains 2 lines and the right hand one contains 3 lines.