In the series 9 N ! 3 P Q 6 E 1 V # 8 L 2 Z 7 A, how many pairs of letters are there with as many elements between them in the series as there are letters between them in the English alphabet?

The letters and their places are N (2), P (5), Q (6), E (8), V (10), L (13), Z (15), A (17). Four pairs match. N and V: seven elements lie between them in the series, and N is the 14th letter and V the 22nd, so seven letters lie between them in the alphabet. P and Q: none between in the series and none in the alphabet. P and Z: nine between in the series, and P (16th) to Z (26th) leaves nine in the alphabet. Q and Z: eight between in the series and eight in the alphabet. No other pair matches, so the answer is 4. Answering 3 comes of overlooking the neighbouring pair P and Q, whose count is nought on both sides; 5 comes of counting places rather than the elements between them; 2 of testing only pairs that stand close together.