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A Number Lock has 3 digit key. ###
that should fulfil the following conditions:
6 8 2 - One Number is well placed and correct.
6 1 4 - One Number is correct but wrong placed.
2 0 6 - Two Numbers are correct but wrong placed.
7 3 8 - Nothing is correct.
7 8 0 - One Number is correct but wrong placed.
Can you crack the code ?
0 4 2
Because
One of
6 8 2is correct and the right spot. By the second line, we can eliminate6, which didn't change position, but would now have to be in the wrong spot. By the 5th line, we eliminate8, as well. This means that the code isx x 2.
The third line tells us that0is in the code, but not in the middle or last position. The code is now0 x 2. Neither of these numbers appears in the second line, which indicates that either1or4is correct, but not in the right spot. The only one of these two not in the middle is4, therefore, the code is0 4 2.
042
because:
4 tells us no 7,3,8, therefore by 5, 0 is in it. 3 tells us 0 is first. 1 then tells us 2 is last. 3 tells us 6 isn't in it, and 2 tells us 4 is in the middle.
