Escape RoomRiddle #1407
Three guesses are scratched beside a three-digit lock. 810: one digit is right and in the right spot, and one is right but in the wrong spot. 038: one digit is right and in the right spot. 907: nothing is right. 573: one digit is right and in the right spot. What's the code?
Hint: Start with 907. It tells you three digits you can cross off everywhere else.
Answer
518
907 rules out 9, 0 and 7. 810 then says both 8 and 1 are in the code. In 038, if 3 were the placed digit, 8 would have to be missing, which contradicts 810, so 8 is right and last. In 810, 8 is now misplaced, so 1 is placed, in the middle. In 573, 7 is out and the last spot is taken, so 5 is first: 518. A brute-force check of all 1,000 codes confirms only 518 fits.
Did you get it?
Nice work. On to the next one.
Got you this time. Try the next one.
