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Problems
Contests
National and Regional Contests
Turkey Contests
National Olympiad First Round
2001 National Olympiad First Round
27
27
Part of
2001 National Olympiad First Round
Problems
(1)
P27 [Number Theory] - Turkish NMO 1st Round - 2001
Source:
4/23/2014
If decimal representation of
2
n
2^n
2
n
starts with
7
7
7
, what is the first digit in decimal representation of
5
n
5^n
5
n
?
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A
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1
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B
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3
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C
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5
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D
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7
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9
<span class='latex-bold'>(A)</span>\ 1 \qquad<span class='latex-bold'>(B)</span>\ 3 \qquad<span class='latex-bold'>(C)</span>\ 5 \qquad<span class='latex-bold'>(D)</span>\ 7 \qquad<span class='latex-bold'>(E)</span>\ 9
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3
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C
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5
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D
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7
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E
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9