MathDB
Problems
Contests
International Contests
Tournament Of Towns
1992 Tournament Of Towns
(324) 1
(324) 1
Part of
1992 Tournament Of Towns
Problems
(1)
TOT 324 1992 Spring A J1 crowded collections of numbers
Source:
6/9/2024
A collection of
n
>
2
n > 2
n
>
2
numbers is called crowded if each of them is less than their sum divided by
n
−
1
n - 1
n
−
1
. Let
{
a
,
b
,
c
,
,
.
.
.
}
\{a, b, c, ,...\}
{
a
,
b
,
c
,,
...
}
be a crowded collection of
n
n
n
numbers whose sum equals
S
S
S
. Prove that:(a) each of the numbers is positive, (b) we always have
a
+
b
>
c
a + b > c
a
+
b
>
c
, (c) we always have
a
+
b
≥
S
n
−
1
a + b \ge \frac{S}{n-1}
a
+
b
≥
n
−
1
S
. (Regina Schleifer)
number theory
algebra