Which of the following letter-clusters will replace the question mark (?) in the given series to make it logically complete?
MF 99, OD 109, ?, SZ 129. UX 139
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. QB 119.
Given series: MF 99, OD 109, ?, SZ 129, UX 139
M + 2 = O; O + 2 = Q; Q + 2 = S; S + 2 = U
F - 2 = D; D D - 2 = B; B - 2 = Z; Z - 2 = X
99 + 10 = 109; 109 + 10 = 119; 119 + 10 = 129; 129 + 10 = 139