Puzzles - Missing letters puzzles

Exercise : Missing letters puzzles
139.
Answer
:
V
Explanation
:
Starting with the top left triangle, and moving clockwise around the other 2, letters advance through the alphabet in steps of 4, 5 and 6, with their relative positions moving 1 place clockwise around each triangle.

140.
Answer
:
M
Explanation
:
As you move down the line of letters, alphabetical values increase by 7, then 4, then 7 etc.

141.
Answer
:
D
Explanation
:
Starting on the top left, and moving to the right, then down one row and to the left etc. in a snakes and ladders pattern, letters advance through the alphabet in steps of 5, then 2, then 5 etc.