Puzzles - Missing letters puzzles

Answer

:

Y

Explanation

:

Start with the outer segment in the top left, and move anti-clockwise. Letters advance through the alphabet in steps of 6, then 7, then 8. Continue around the outer segments of the diagram, then move in an anti-clockwise direction around the inner segments.

Answer

:

R

Explanation

:

Working from top to bottom, letters move through the alphabet in steps of 2, then 3, then 2 etc.

Answer

:

I

Explanation

:

Starting with the top two segments, the sum of the numerical values of letters in adjoining segments equals 20.