When all words in "MASTER" is sorted in alphabetical order then what is the…

Answer: AREMST

1. Arrange the letters of MASTER in alphabetical order: A E M R S T.

2. For a fixed first letter there are 5! = 120 permutations. So all words starting with A occupy positions 1–120. The 49th word therefore starts with A.

3. Fix the second letter (from the remaining letters E, M, R, S, T). For each choice there are 4! = 24 permutations.

4. Words starting with A E occupy ranks 1–24; A M occupy ranks 25–48; A R occupy ranks 49–72. Thus the 49th word is the first word in the A R block.

5. Within the A R block, arrange the remaining letters in alphabetical order: E, M, S, T. The first word in this block is A R E M S T.

Therefore the 49th word is AREMST.