Select the option that can replace the question mark (?) in the following series.
NB, OA, PZ, QY, ?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. RX.
N + 1 = O, O + 1 = P, P + 1 = Q, Q + 1 = R
B - 1 - A, A - 1 =Z, Z - 1 = Y, Y - 1 = X