Answer is "o" because
a(first letter)-F(6th letter)=different of 5 x+y
difference z to u = 5 x-y
difference g to l i= 5 x+y
difference t to o = 5 x-y
The next block of four letters would be MRNI, because you start a new block with letters that are 6 places later in the alphabet than the one that comes four places earlier in the sequence
o
E G F A G B A Every other letter is in alphabetical
g.
T
k
Here is the pattern. It begins with the first letter of the alphabet and then "adds" five letters. The next letter comes from the end of the alpahabet and "subtracts" five letters. The fifth in the series (G) adds one off from the second (F). If one adds five to that the sixth in the series (L) comes next. We then move to the letter before "U" to get the seventh in the series. To sum it all: We added five to get from the A to F and G to L. We subtracted five to get from Z to U. To answer the question, we subtract five from T to get O I think!
o
d
Answer is "o" because a(first letter)-F(6th letter)=different of 5 x+y difference z to u = 5 x-y difference g to l i= 5 x+y difference t to o = 5 x-y
k comes next, and then l.
O
G
The next letter is D. The pattern is every fourth letter. Ie. a b c D e f g H i j k L m n o P and so on...