MathDB

31

Part of 2002 National Olympiad First Round

Problems(1)

P31 [Combinatorics] - Turkish NMO 1st Round - 2002

Source:

8/11/2014
The numbers 1,2,…,N1, 2, \dots ,N are arranged in a circle where N \geq  2. If each number shares a common digit with each of its neighbours in decimal representation, what is the least possible value of NN?
<spanclass=′latex−bold′>a)</span> 18<spanclass=′latex−bold′>b)</span> 19<spanclass=′latex−bold′>c)</span> 28<spanclass=′latex−bold′>d)</span> 29<spanclass=′latex−bold′>e)</span> None of above <span class='latex-bold'>a)</span>\ 18 \qquad<span class='latex-bold'>b)</span>\ 19 \qquad<span class='latex-bold'>c)</span>\ 28 \qquad<span class='latex-bold'>d)</span>\ 29 \qquad<span class='latex-bold'>e)</span>\ \text{None of above}