MathDB

24

Part of 2007 National Olympiad First Round

Problems(1)

Turkey NMO 2007 1st Round - P24 (Combinatorics)

Source:

10/5/2012
The integers from 11 to nn are arranged along a circle such that each number is a multiple of difference of its adjacents. For which nn below such an arrangement is possible?
<spanclass=′latex−bold′>(A)</span> 5<spanclass=′latex−bold′>(B)</span> 6<spanclass=′latex−bold′>(C)</span> 7<spanclass=′latex−bold′>(D)</span> 9<spanclass=′latex−bold′>(E)</span> 13 <span class='latex-bold'>(A)</span>\ 5 \qquad<span class='latex-bold'>(B)</span>\ 6 \qquad<span class='latex-bold'>(C)</span>\ 7 \qquad<span class='latex-bold'>(D)</span>\ 9 \qquad<span class='latex-bold'>(E)</span>\ 13