BEAR + RARE + ERE = RHYME
Each letter represents a different digit, encoding a valid equation.
What’s the equation?
Adding the last digits gives R + E+ E = E mod 10 which requires R + E = 10
R must = 1 because the maximum sum of two 4-digit and one 3-digit number is less than 20K if the leading digits of the larger numbers cannot both be 9’s. And that requires E = 9
B + R + carry must either be 10 or else be >= 12 since the 1 is already taken and the sum must be >= 10. But the max carry is 2 and the max B is 8 so B + R + carry <= 11. Which requires that B + R + carry = 10 and H = 0. And since A >= 2 (0 and 1 are in use), the previous column gives 18 + A >= 20 making the carry 2, which requires B = 7.
From the tens digits we have A + 3 (R + R + carry from the ones) = M mod 10, and neither A nor M can be in (0, 1, 7, 9) The allowed values of A, then, are: 2, 3, 5, and there's no carry from the tens into the hundreds. But from the hundreds digits we have 18 + A = Y mod 10, and that excludes A = 2 or 3 since Y can’t be 0 or 1. So A = 5.
Since A = 5, that requires M = 8 and Y = 3 and that’s all the digits:
7951 + 1519 + 919 = 10389 is therefore the only solution.
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Posted by Paul
on 2021-04-13 15:04:34 |