Techniques to improve reliability - Part 10
Solution:
(1) First, go through the clues one by one and consider whether the clue is potentially relevant:
Clue 1: Miss Scarlett was the only person in the lounge. This clue is not relevant.
Clue 2: The person with the pipe was in the kitchen. This clue is not relevant.
Clue 3: Colonel Mustard was the only person in the observatory. This clue is relevant.