Count each 8 which is not immediately preceded by 6 but is immediately followed by either 3 or 4. How many such 8's are there?
6 8 3 7 6 8 4 9 4 8 4 3 6 8 3 8 4 5 9 3 7 8 9

Correct option is D

Given:

Sequence: 6 8 3 7 6 8 4 9 4 8 4 3 6 8 3 8 4 5 9 3 7 8 9
We need to count each 8 that satisfies the following conditions:
1. Is not immediately preceded by 6.
2. Is immediately followed by either 3 or 4.

Formula Used:

Check the sequence for each occurrence of 8:
- If Sequence[i] = 8, ensure:
- Sequence[i-1] ≠ 6 (not preceded by 6).
- Sequence[i+1] = 3 or Sequence[i+1] = 4 (followed by 3 or 4).

Solution:

Analyze each 8 in the sequence:

Total count of valid 8's: 2