it's very simple, i think you didnt think at all :) it is letter S
the next letter would be 'b'
f
E
E. Eight.
d
l
G
The next letter is L. Here is the sequence: a _ _ de _ _ hi _ _ lm.
When you answer sequence questions, look for a repetition anywhere. We can see that the first letter and the last letter is an 'F' so the sequence must be FHEXFHEXF.... so your answer is F.
N (First, Second, Third, Fourth, Fifth, Sixth, Seventh, Eighth, Ninth)
k... for king think deck of cards
G comes next in the musical note sequence. After G, the sequence starts again at A.