Q. Consider the sequence A_BCD_BBCDABC_DABC_D that follows a certain pattern.

Explanation : 

Solution Steps

1. Let’s split the sequence in sets of 5 character: A_BCD_BBCDABC_DABC_D Splits into: A_BCD / _BBCD / ABC_D / ABC_D
2. Analyzing this grouping, we can identify the pattern:
   • Each group consists of 5 characters
   • The pattern involves repeating ABCD in various arrangements, sometimes with repetitions
3. The correct grouping of the sequence by Hit & Trail Method is: A A BCD A BBCD ABC C D ABC D D (Hit & Trail)
4. Observations from this pattern:
   • The first group has two A’s followed by BCD
   • The second group starts with A, then has two B’s, followed by CD
   • The third group has ABC, then C, then D
   • The fourth group has ABC, then two D’s
5. The last group in our given sequence is incomplete: ABC_D
6. To complete it according to the established pattern, we need to add another D, making it: ABC D D
7. Therefore, the missing letters are A, A, C, D