In the letter series, some of the letters are missing. Complete the given…
2024
In the letter series, some of the letters are missing. Complete the given letter series by choosing the correct alternatives from the options given below. b_b_bb__bbb_bb_b
Answer: C. a b a b a b — ConceptIn a missing-letter series, infer the smallest repeating block that explains every fixed letter. The same block must fit the whole series without…
- A.
b b b b b a
- B.
b b a a a b
- C.
a b a b a b
- D.
a a b a a b
Attempted by 2 students.
Show answer & explanation
Correct answer: C
Concept
In a missing-letter series, infer the smallest repeating block that explains every fixed letter. The same block must fit the whole series without changing its length or internal order.
Treat each blank as an unknown position, test the candidate letters in order, and then regroup the completed string to verify the repetition.
Application
Number the six blanks from left to right. Their positions in the 16-character series are 2, 4, 7, 8, 12, and 15.
Insert a, b, a, b, a, b in those positions. The completed series becomes b a b b b b a b b b b a b b b b.
Regroup it as b | abbbb | abbbb | abbbb. After the initial b, the five-letter block abbbb repeats three times.
Cross-check
Reading the repeated blocks from left to right places a at positions 2, 7, and 12 and b in the other three blanks, exactly giving a b a b a b.
Therefore, the missing letters are a b a b a b.