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Problems
Contests
International Contests
IMO Longlists
1984 IMO Longlists
35
35
Part of
1984 IMO Longlists
Problems
(1)
Finding natural numbers satisfying inequality
Source:
10/9/2010
Prove that there exist distinct natural numbers
m
1
,
m
2
,
⋯
,
m
k
m_1,m_2, \cdots , m_k
m
1
,
m
2
,
⋯
,
m
k
satisfying the conditions
π
−
1984
<
25
−
(
1
m
1
+
1
m
2
+
⋯
+
1
m
k
)
<
π
−
1960
\pi^{-1984}<25-\left(\frac{1}{m_1}+\frac{1}{m_2}+\cdots+\frac{1}{m_k}\right)<\pi^{-1960}
π
−
1984
<
25
−
(
m
1
1
+
m
2
1
+
⋯
+
m
k
1
)
<
π
−
1960
where
π
\pi
π
is the ratio between a circle and its diameter.
inequalities
ratio
inequalities unsolved