MathDB
Sum of Consecutive Integers Dividing 6n

Source:

January 12, 2009

Problem Statement

For how many positive integers n n does 1 \plus{} 2 \plus{} \cdots \plus{} n evenly divide from 6n 6n? <spanclass=latexbold>(A)</span> 3<spanclass=latexbold>(B)</span> 5<spanclass=latexbold>(C)</span> 7<spanclass=latexbold>(D)</span> 9<spanclass=latexbold>(E)</span> 11 <span class='latex-bold'>(A)</span>\ 3\qquad <span class='latex-bold'>(B)</span>\ 5\qquad <span class='latex-bold'>(C)</span>\ 7\qquad <span class='latex-bold'>(D)</span>\ 9\qquad <span class='latex-bold'>(E)</span>\ 11