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Is a^2 + b^2 + c^2 a perfect square?

Source: 0

April 28, 2009
modular arithmetic

Problem Statement

How many of 11^2 \plus{} 13^2 \plus{} 17^2, 24^2 \plus{} 25^2 \plus{} 26^2, 12^2 \plus{} 24^2 \plus{} 36^2, 11^2 \plus{} 12^2 \plus{} 132^2 are perfect square ?
<spanclass=latexbold>(A)</span> 4<spanclass=latexbold>(B)</span> 3<spanclass=latexbold>(C)</span> 2d)1<spanclass=latexbold>(E)</span> 0<span class='latex-bold'>(A)</span>\ 4 \qquad<span class='latex-bold'>(B)</span>\ 3 \qquad<span class='latex-bold'>(C)</span>\ 2 d)1 \qquad<span class='latex-bold'>(E)</span>\ 0