BRAIN TRIVIA
Solution:
8254
Explanation:
Code breakers: find the correct 4-digit combination using the numbers 1-9, with no repeats:
1 9 5 7 - 1 digit is correct and in the correct position
4 3 6 8 - 2 digits are correct but in the wrong positions
9 6 7 3 - None of the digits are correct
1 5 9 6 - 1 digit is correct but in the wrong position
From clue 3, you can remove those numbers from all of the other clues. This leaves us with:
1
957- 1 digit is correct and in the correct position4
3 68 - 2 digits are correct but in the wrong positions9 6 7 3- None of the digits are correct1 5
9 6- 1 digit is correct but in the wrong position
From clue 2, this means 4 and 8 are both correct but in the wrong positions. So, the first digit is 8 and the last digit is 4.
From clues 1 and 4, the correct digit must be 5 in the third spot.
If the final (second) digit cannot be 1 (from clues 1 and 4), 3, 6, 7, or 9 (from clue 3), or 4 or 5 or 8 (because no digits are repeated), then the second digit must be 2.