In the given series, identify how many pairs of letters appear in exact…

Concept: Two adjacent letters in a sequence are said to appear in exact alphabetical order when the second letter is the immediate successor of the first letter in the English alphabet, i.e. their alphabet positions differ by exactly one (for example, K followed by L). Counting such pairs means checking every adjacent letter pair in the series against this single successor rule.

Application: The sixteen letters of the series, in order, are C, A, B, E, G, H, D, L, M, Q, R, F, T, S, U, W. Checking each of the fifteen adjacent pairs against the successor rule:

1. C then A: A is not the letter immediately after C in the alphabet.

2. A then B: B is exactly the letter after A, so this pair satisfies the rule.

3. B then E: E is not the letter immediately after B.

4. E then G: G is not the letter immediately after E.

5. G then H: H is exactly the letter after G, so this pair satisfies the rule.

6. H then D: D is not the letter immediately after H.

7. D then L: L is not the letter immediately after D.

8. L then M: M is exactly the letter after L, so this pair satisfies the rule.

9. M then Q: Q is not the letter immediately after M.

10. Q then R: R is exactly the letter after Q, so this pair satisfies the rule.

11. R then F: F is not the letter immediately after R.

12. F then T: T is not the letter immediately after F.

13. T then S: S is not the letter immediately after T (S in fact precedes T).

14. S then U: U is not the letter immediately after S.

15. U then W: W is not the letter immediately after U.

Cross-check: Re-scanning the pairs that satisfied the rule — (A, B), (G, H), (L, M), (Q, R) — confirms that in each case the second letter's alphabet position is exactly one more than the first letter's position, and no other adjacent pair in the series meets this condition.

So the series contains 4 pairs of letters in exact alphabetical order.