SPOILER WARNING FOR ANYONE WHO HASEN’T PLAYED 007 FIRST LIGHT
I was playing 007: First light (the new james bond video games), and there was a puzzle to unlock one of the doors and it went as follows:
Digit #1: I am one
Digit #2: I am two digits higher than digit 3
Digit #3: I am two digits higher than digit 4
Digit #4: I am ten digits less than digits 3 and 2 combined
I tried brute forcing my way through the problem but gave up and looked on reddit. It’s when I saw a comment of someone explaining how you can solve it mathematically which didn’t even cross my mind at the time and it’s actually insanely easy to solve using
x = the 4th digit
x+2 = the second digit
x+4 = the third digit
then of course - 10
which gives you x = 4 and the solution to the problem.
This was probably the coolest application of math I’ve seen and would really like to know more about it.