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Mediterranean Mathematics Olympiad
2010 Mediterranean Mathematics Olympiad
2
Mediterranean M.C. 2010 Problem 2
Mediterranean M.C. 2010 Problem 2
Source:
July 11, 2010
inequalities
inequalities proposed
Mediterranean
n-variable inequality
Problem Statement
Given the positive real numbers
a
1
,
a
2
,
…
,
a
n
,
a_{1},a_{2},\dots,a_{n},
a
1
,
a
2
,
…
,
a
n
,
such that
n
>
2
n>2
n
>
2
and
a
1
+
a
2
+
⋯
+
a
n
=
1
,
a_{1}+a_{2}+\dots+a_{n}=1,
a
1
+
a
2
+
⋯
+
a
n
=
1
,
prove that the inequality
a
2
⋅
a
3
⋅
⋯
⋅
a
n
a
1
+
n
−
2
+
a
1
⋅
a
3
⋅
⋯
⋅
a
n
a
2
+
n
−
2
+
⋯
+
a
1
⋅
a
2
⋅
⋯
⋅
a
n
−
1
a
n
+
n
−
2
≤
1
(
n
−
1
)
2
\frac{a_{2}\cdot a_{3}\cdot\dots\cdot a_{n}}{a_{1}+n-2}+\frac{a_{1}\cdot a_{3}\cdot\dots\cdot a_{n}}{a_{2}+n-2}+\dots+\frac{a_{1}\cdot a_{2}\cdot\dots\cdot a_{n-1}}{a_{n}+n-2}\leq\frac{1}{\left(n-1\right)^{2}}
a
1
+
n
−
2
a
2
⋅
a
3
⋅
⋯
⋅
a
n
+
a
2
+
n
−
2
a
1
⋅
a
3
⋅
⋯
⋅
a
n
+
⋯
+
a
n
+
n
−
2
a
1
⋅
a
2
⋅
⋯
⋅
a
n
−
1
≤
(
n
−
1
)
2
1
does holds.
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