Letter series type of questions usually consists of a series of small letters which follow a certain pattern. However, some letters are missing from the series. These missing letters are then given in a proper sequence as one of the alternatives. The candidate is requitred to choose this alternative as the answer.
_ A D A C B _ _ B D C C 1 3 _ _ 1 2 4 2 _ _ _ _ a _ _ b _ _ c d ? ? ? ?
Clearly, b corresponds to A.
1 corresponds to C and a corresponds to 1.
So, a corresponds to C.
2 corresponds to B and d corresponds to 2.
So, d corresponds to B.
So, the remaining lettter i.e., c corresponds to D.
Thus, BDCC corresponds to d, c, a, a.