Letter Series (Logical Reasoning)

ST

CD, GH, KL, OP, ____ (Multiple letters: If the letters in each set of letters are alphabetically arranged, a pattern may emerge from every last letter of a preceding set to the first letter of its next set)

R

D, F, I, M, ___ (A pattern from the number of letters needed to reach the next letter may emerge)

EEEEEEEEEE

E, EE, EEEE, EEEEEEE, E___________ (The cardinality/number of letters can be a sequence in itself)

G

A, E, C, F, E, G, ___ (The sequence can have two independent patterns in it. 1st pattern occurs on the 1st, 3rd, 5th,... letter; 2nd pattern occurs on the 2nd, 4th, 6th... letter)

T

B, Z, X, V, ___ A sequence may involve every nth letter before the previous letter)

NO

BC, A, EF, B, IJ, C, ____ (Multiple letters: The set of letters can have two independent patterns in it. 1st pattern occurs on the 1st, 3rd, 5th,... letter; 2nd pattern occurs on the 2nd, 4th, 6th... letter)

FCY

BCC, CCB, DCA, ECZ, ____ (Multiple letters: every nth letter can be a sequence that has a pattern in itself)

NPOQ

BDCE, FHGI, JLKM, _____ (Multiple letters: letters may change positions in a set)

O

C, F, I, L, ___ (A sequence may involve every nth letter after the previous letter)

QRST

H, JK, MNO, ____ (A sequence may have two or more combinations of patterns)

F

J, I, H, G, ___ (Reverse alphabetically arranged)

O

K, L, M, N, ___ (Alphabetically arranged)

DF

RT, UW, XZ, AC, ___ (Multiple letters: A set may involve skipped/missing letters)