Question : Directions: Select the combination of letters that when sequentially placed in the blanks of the given series will make the series logically complete.
AEI_JL_QS_SS_ZXU

Option 1: BLSN

Option 2: SSUU

Option 3: SDMA

Option 4: ONSB

Correct Answer: ONSB

Solution : Given:
AEI_JL_QS_SS_ZXU

To fill the series we have to divide the series – AEI_/ JL_Q / S_SS / _ZXU
Let's check each option –
First option: BLSN ; AEI B / JL L Q / S S SS / N ZXU (No pattern has been found.)
Second option: SSUU ; AEI S / JL S Q / S U SS / U ZXU (No pattern has been found.)
Third option: SDMA ; AEI S / JL D Q / S M SS / A ZXU (No pattern has been found.)
Fourth option: ONSB ; AEI O / JL N Q / S S SS / B ZXU
(The following pattern is observed –
First letter of each part→A + 9 = J; J + 9 = S; S + 9 = B;
Second letter of each part→E + 7 = L; L + 7 =S; S + 7 = Z
Third letter of each part→I + 5 = N; N + 5 =S; S + 5 = X
Fourth letter of each part→O + 2 = Q; Q + 2 = S; S + 2 = U)

So, the series becomes→ AEIOJLNQSSSSBZXU . Hence, the fourth option is correct.