The series is ADBC ACBD ABED DEBA DBCA CBDA.

Thus, the letters are equidistant from the beginning and the end of series.

Here,

W + 3 = Z

S + 3 = V

O + 3 = R

Similarly,

J + 3 = M

F + 3 = I

B + 3 = E

The pattern of letters in the series is :

MNOM MNOM MNOM MNOM

According to the English alphabetical series:

L – 11 = A

N – 11 = C

P – 11 = E

Q – 11 = F

Similarly,

T – 11 = I

U – 11 = J

X – 11 = M

Y – 11 = N

Study the pattern carefully. In the first segment, two letters face right and the next two face left. The first letter in the second segment repeats the last letter of the previous segment. The same is true for the third segment. But the fourth segment changes again; it is the opposite of the first segment, so the last two letters must face right.

Because the letters are the same, concentrate on the number series, which is a simple 2, 3, 4, 5, 6 series, and follows each letter in order.

This is an alternating series. The first and third segments are repeated. The second segment is simply upside down.

In this series, the third letter is repeated as the first letter of the next segment. The middle letter, A, remains static. The third letters are in alphabetical order, beginning with R.

The first two letters, PQ, are static. The third letter is in alphabetical order, beginning with R. The number series is in descending order beginning with 5.

This is an alternating series in alphabetical order. The middle letters follow the order ABCDE. The first and third letters are alphabetical beginning with J. The third letter is repeated as the first letter in each subsequent three-letter segment.

The first letters are in alphabetical order with a letter skipped in between each segment: C, E, G, I, K. The second and third letters are repeated; they are also in order with a skipped letter: M, O, Q, S, U.

Look for opposites in this series of figures. The first and second segments are opposites of each other. The same is true for the third and fourth segments.

There are two alphabetical series here. The first series is with the first letters only: STUVW. The second series involves the remaining letters: CD, EF, GH, IJ, KL.