Which letter-cluster will replace the question mark (?) and complete the given series?
CURB, ESPC, ?, IOLE, KMJF
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1, i.e., GQND
C + 2 = E, E + 2 = G, G + 2 = I. I + 2 = K,
U - 2 = S, S - 2 = Q, Q - 2 = O, O - 2 = M
R - 2 = P, P - 2 = N, N - 2 = L, L - 2 = J
B +1 = C, C + 1 = D, D + 1 = E, E + 1 = F