Study the following arrangement carefully and answer the question.
2 6 3 7 5 6 4 2 9 6 1 3 4 1 6 3 9 1 5 6 9 2 3 1 6 5 4 3 2 1 9 6 7 1 6 3
How many 6s are there in the series, each of which is immediately preceded by 1 or 5 and immediately followed by 3 or 9?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Three
Check every 6 in the series: the digit before it must be 1 or 5, and the digit after it must be 3 or 9.
Place 2: 2 6 3 — does not count (preceded by 2)
Place 6: 5 6 4 — does not count (followed by 4)
Place 10: 9 6 1 — does not count (preceded by 9)
Place 15: 1 6 3 — counts
Place 20: 5 6 9 — counts
Place 25: 1 6 5 — does not count (followed by 5)
Place 32: 9 6 7 — does not count (preceded by 9)
Place 35: 1 6 3 — counts
Three of the 6s meet both conditions, so the answer is three.