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Putnam
1992 Putnam
B1
B1
Part of
1992 Putnam
Problems
(1)
Putnam 1992 B1
Source: Putnam 1992
7/18/2022
Let
S
S
S
be a set of
n
n
n
distinct real numbers. Let
A
S
A_{S}
A
S
be the set of numbers that occur as averages of two distinct elements of
S
S
S
. For a given
n
≥
2
n \geq 2
n
≥
2
, what is the smallest possible number of elements in
A
S
A_{S}
A
S
?
Putnam
Average
set theory