9514 1404 393
Answer:
042
Step-by-step explanation:
The first clue tells you the possibilities are ...
6__, _8_, or __2
The second clue eliminates 6__ and tells you the possibilities are ...
18_, _81, 1_2, 48_, _42
The third clue tells you two of the correct digits are 0 and 2, since 6 has already been eliminated by the first two clues. This only leaves 042.
042 is consistent with the last 2 clues.
The 3-digit key is 042.
