The letters move five steps forward.

The series consists of 2 groups (A, B, C, D, E, F, ?, ?) and (N, O, P, ?). The series is made of two terms of first group followed by one term of second group.

$$\begin{gathered} b w x y z a \\ d s t u v c \\ f o p q r e \end{gathered}$$

New sequence is as follows:

pr1  qr2  pr3  pq4  qr5  rp6  qq7  rp8  qp9  qr10  qp11  qp12

16th from the right  end is 7

Here it can be seen that it is not a continuous series.

so take alternative terms.

CGE, FJH, IMK and RNP, OKM,__

Between R and O there is a gap of two letters. so the first letter in the answer is L.Proceding like this the answer is LHJ

The first letter moves three steps forward. The second letter moves two steps forward. The third letter moves three steps forward.

Here the given number series 625, 625, 600, ?, 475, 875 follows a pattern that

625

625 + (0 x 0) = 625

625 - (5 x 5) = 625 - 25 = 600

600 + (10 x 10) = 600 + 100 = 700

700 - (15 x 15) = 700 - 225 = 475

475 + (20 x 20) = 475 + 400 = 875

Hence, the missing number in the given number series is 700.

The given number series 999, 990, 998, 991, 997, 992, ?

It follows a pattern that,

999

999 - 9 = 990

990 + 8 = 998

998 - 7 = 991

991 + 6 = 997

997 - 5 = 992

992 + 4 = 996

Hence, the next number in the given number series is 996.

The pattern is + 6, + 12, + 18, +24 ...........So the missing term is = 68 +30 = 98