All of the letters in the word ‘WISDOM’ are arranged in alphabetical order. How many letters are there in the English alphabetical series between the letter which is third from the left end and the one which is second from the right end in the new letter- cluster thus formed?

Correct — C. Sort the letters first, then count the gap.

WISDOM contains W, I, S, D, O and M. In alphabetical order: D, I, M, O, S, W.

Third from the left end is M.
Second from the right end is S.

M is the 13th letter and S is the 19th, so the count strictly between them is 19 − 13 − 1.

Those letters are N, O, P, Q and R — five in all, option (c).

Why the others are wrong

• (a)
  Three — Option (a) is what you get by counting both anchors from the same end. Both from the left gives M and I, both from the right gives O and S, and each of those pairs has exactly three letters between it.
• (b)
  Six — Option (b) counts an endpoint in. Between means strictly between, so M and S are themselves excluded and only N, O, P, Q and R remain.
• (d)
  Two — Option (d) matches no pair from the sorted cluster. Across D, I, M, O, S, W the between-counts for neighbouring letters are 4, 3, 1, 3 and 3 — two never occurs.

Two separate skills sit in one line here, and the question is built so that getting either wrong lands you on a printed option.

The first is sorting. WISDOM becomes D, I, M, O, S, W, and everything the question says afterwards refers to that new cluster. The original word is out of play.

The second is the between-count. For letters at positions p and q with q the larger, the number strictly between them is q − p − 1, so 19 − 13 − 1 = 5.

Key facts

• WISDOM arranged in alphabetical order is D, I, M, O, S, W.
• M is the 13th letter of the English alphabet and S is the 19th.
• The number of letters strictly between positions p and q is q minus p minus 1.
• N, O, P, Q and R are the letters lying between M and S.

Common traps

• Answering from the original word instead of the sorted cluster
• Counting both anchors from the same end, which gives three either way
• Including one or both endpoints in the count, which gives six or seven

No directly related past PYQ was found.