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Programming Enigma Puzzles

14 August 2019

Posted by on **From New Scientist #1067, 1st September 1977** [link]

Each digit in the addition sum below is wrong. But the same wrong digit stands for the same correct digit wherever it appears, and the same correct digit is always represented by the same wrong digit.

Find the correct addition sum.

[puzzle16]

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We can use the [[

`SubstitutedSum()`

]] solver from theenigma.pylibrary to solve this puzzle. While it can cope with using the digits as symbols (which cannot stand for themselves). I think it is easier to understand if we replace the digits 1, 4, 7, 8 by the symbols A, B, C, D and solve the equivalent sum: BDA + BDB = CBC.The following run file executes in 137ms.

Run:[ @repl.it ]Solution:The correct sum is: 263 + 262 = 525.