MathDB
Sum of Digits of Square

Source:

February 27, 2008

Problem Statement

The number 2564⋅6425 25^{64}\cdot64^{25} is the square of a positive integer N N. In decimal representation, the sum of the digits of N N is <spanclass=′latex−bold′>(A)</span> 7<spanclass=′latex−bold′>(B)</span> 14<spanclass=′latex−bold′>(C)</span> 21<spanclass=′latex−bold′>(D)</span> 28<spanclass=′latex−bold′>(E)</span> 35 <span class='latex-bold'>(A)</span>\ 7 \qquad <span class='latex-bold'>(B)</span>\ 14 \qquad <span class='latex-bold'>(C)</span>\ 21 \qquad <span class='latex-bold'>(D)</span>\ 28 \qquad <span class='latex-bold'>(E)</span>\ 35
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