MathDB

19

Part of 2002 National Olympiad First Round

Problems(1)

P19 [Combinatorics] - Turkish NMO 1st Round - 2002

Source:

8/10/2014
How many positive integers AA are there such that if we append 33 digits to the rightmost of decimal representation of AA, we will get a number equal to 1+2+⋯+A1+2+\cdots + A?
<spanclass=′latex−bold′>a)</span> 0<spanclass=′latex−bold′>b)</span> 1<spanclass=′latex−bold′>c)</span> 2<spanclass=′latex−bold′>d)</span> 2002<spanclass=′latex−bold′>e)</span> None of above <span class='latex-bold'>a)</span>\ 0 \qquad<span class='latex-bold'>b)</span>\ 1 \qquad<span class='latex-bold'>c)</span>\ 2 \qquad<span class='latex-bold'>d)</span>\ 2002 \qquad<span class='latex-bold'>e)</span>\ \text{None of above}