MathDB
GCD Condition

Source: 2022 AMC 12B #16

November 17, 2021
number theorygreatest common divisorAMCAMC 12AMC 12 B

Problem Statement

Let a,b,a, b, and cc be positive integers such that a+b+c=23a+b+c=23 and gcd(a,b)+gcd(b,c)+gcd(c,a)=9.\gcd(a,b)+\gcd(b,c)+\gcd(c,a)=9. What is the sum of all possible distinct values of a2+b2+c2a^{2}+b^{2}+c^{2}?
<spanclass=latexbold>(A)</span> 259<spanclass=latexbold>(B)</span> 438<spanclass=latexbold>(C)</span> 516<spanclass=latexbold>(D)</span> 625<spanclass=latexbold>(E)</span> 687<span class='latex-bold'>(A)</span> ~259\qquad<span class='latex-bold'>(B)</span> ~438\qquad<span class='latex-bold'>(C)</span> ~516\qquad<span class='latex-bold'>(D)</span> ~625\qquad<span class='latex-bold'>(E)</span> ~687
Proposed by djmathman