The position of how many letters will remain unchanged if each of the letters in the word ‘DELIGHT’ is arranged in the English alphabetical order?

Correct — C. Write the word against its alphabetical rearrangement, one letter per column.

DELIGHT is D E L I G H T
Sorted, it is D E G H I L T

Column 1: D against D, same. Column 2: E against E, same. Columns 3 to 6: L against G, I against H, G against I, H against L — all four move. Column 7: T against T, same.

Rule: a letter keeps its place when its rank among the word's letters equals its position in the word. D, E and T qualify, which is three → option (c).

Why the others are wrong

• (a)
  One — One is what you get by spotting T at the end and stopping there. D and E already stand in alphabetical order at the front and also hold their columns.
• (b)
  None — None assumes every letter has to move. D and E are the two smallest letters of DELIGHT and they already occupy positions 1 and 2, so they cannot shift.
• (d)
  Two — Two counts the front pair D and E and misses T, which is both the last letter of the word and the last letter alphabetically.

Sorting the letters and comparing column by column is the whole method. What saves marks is how you write it: the word on one line, the sorted letters directly beneath, then tick the columns where the two agree.

Underneath is a rank test. A letter keeps its place exactly when its rank among the letters of that word equals its position in the word.

D is the smallest letter of DELIGHT and stands first, E is the second smallest and stands second, T is the largest and stands seventh. Every other letter has a rank that does not match its slot.

Key facts

• DELIGHT sorted alphabetically is D E G H I L T.
• D, E and T hold their original positions 1, 2 and 7.
• A letter stays put exactly when its rank among the word's letters matches its position in the word.

Common traps

• Sorting from the letters you notice first instead of writing the full sorted list.
• Forgetting the final letter, which is often already in place.
• Counting letters that appear in both lists rather than in the same column.

No directly related past PYQ was found.