In this type of questions, a series of single, pairs or groups of letters or combinations of letters and numerals are given. The terms of the series form a certain pattern as regards the position of the letter in the English alphabet. Find the missing or wrong term in series 

1)

A, B, B, D, C, F, D, H, E, ?, ?


A) E, F

B) F, G

C) J, F

D) F, I

E) J, K

Answer:

Option C

Explanation:

The given sequence is a combination of two series:

I; 1st, 3rd, 5th, 7th,  9th, 11th terms ie., A, B, C, D, E, ?

II; 2nd, 4th, 6th, 8th, 10th terms ie., B, D, F, H, ?

Clearly, I consists of consecutive letters while II consists of  alternate letters. So, the missing letter in I is F, while the missing letter in II is J. So the missing terms are J and F respectively.

Hence the answer is (c).