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Problems
Contests
National and Regional Contests
Canada Contests
Canada National Olympiad
2016 Canada National Olympiad
1
1
Part of
2016 Canada National Olympiad
Problems
(1)
Averaging Sequneces
Source: 2016 CMO #1
4/10/2016
The integers
1
,
2
,
3
,
…
,
2016
1, 2, 3, \ldots, 2016
1
,
2
,
3
,
…
,
2016
are written on a board. You can choose any two numbers on the board and replace them with their average. For example, you can replace
1
1
1
and
2
2
2
with
1.5
1.5
1.5
, or you can replace
1
1
1
and
3
3
3
with a second copy of
2
2
2
. After
2015
2015
2015
replacements of this kind, the board will have only one number left on it.(a) Prove that there is a sequence of replacements that will make the final number equal to
2
2
2
.(b) Prove that there is a sequence of replacements that will make the final number equal to
1000
1000
1000
.
Sequence