Puzzle for July 4, 2022  ( )

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Find the 6-digit number ABCDEF by solving the following equations:

eq.1) A + B + C + D + E + F = 33 eq.2) C = B + E eq.3) D = A + C eq.4) C + E = A + D eq.5) E – B = B – A eq.6) B + C = A + F

A, B, C, D, E, and F each represent a one-digit non-negative integer.

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Hint #1


In eq.4, replace D with A + C (from eq.3): C + E = A + A + C which becomes C + E = 2×A + C Subtract C from each side of the equation above: C + E – C = 2×A + C – C which makes E = 2×A


  

Hint #2


In eq.5, replace E with 2×A: 2×A – B = B – A Add B and A to both sides of the above equation: 2×A – B + B + A = B – A + B + A which makes 3×A = 2×B Divide both sides by 2: 3×A ÷ 2 = 2×B ÷ 2 which makes 1½×A = B


  

Hint #3


In eq.2, substitute 1½×A for B, and 2×A for E: C = 1½×A + 2×A which makes C = 3½×A


  

Hint #4


Substitute 3½×A for C in eq.3: D = A + 3½×A which makes D = 4½×A


  

Hint #5


Substitute 1½×A for B, and 3½×A for C in eq.6: 1½×A + 3½×A = A + F which becomes 5×A = A + F Subtract A from each side of the above equation: 5×A – A = A + F – A which makes 4×A = F


  

Solution

Substitute 1½×A for B, 3½×A for C, 4½×A for D, 2×A for E, and 4×A for F in eq.1: A + 1½×A + 3½×A + 4½×A + 2×A + 4×A = 33 which simplifies to 16½×A = 33 Divide both sides of the above equation by 16½: 16½×A ÷ 16½ = 33 ÷ 16½ which means A = 2 making B = 1½×A = 1½ × 2 = 3 C = 3½×A = 3½ × 2 = 7 D = 4½×A = 4½ × 2 = 9 E = 2×A = 2 × 2 = 4 F = 4×A = 4 × 2 = 8 and ABCDEF = 237948