Select the combination of letters that, when placed in the blanks of the given letter series in order, will complete the series.
d c _ b _ a _ c a _ c a d _ a
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → acdbc
Split the 15 places into five groups of three. Every group ends in c a, and the first letters go d, b, d, b, d in turn.
Group 1: d c _ becomes d c a
Group 2: b _ a becomes b c a
Group 3: _ c a becomes d c a
Group 4: _ c a becomes b c a
Group 5: d _ a becomes d c a
The series is dca bca dca bca dca, and the blanks in order are acdbc.