Find the next number of the given series: 6,4,7,5,8,6,?

Explanation

Split the sequence into two interleaved subsequences:

• Odd positions (1st, 3rd, 5th...): 6, 7, 8 — increases by 1.

• Even positions (2nd, 4th, 6th...): 4, 5, 6 — increases by 1.

The next term is the 7th term (odd position), so continue the odd-position subsequence: 8 → 9. Answer: 9.