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Contests
National and Regional Contests
India Contests
India Pre-Regional Mathematical Olympiad
2014 India PRMO
20
20
Part of
2014 India PRMO
Problems
(1)
2014 preRMO p20, A,B subsets of {1,2,..., 5}
Source:
8/9/2019
What is the number of ordered pairs
(
A
,
B
)
(A,B)
(
A
,
B
)
where
A
A
A
and
B
B
B
are subsets of
{
1
,
2
,
.
.
.
,
5
}
\{1,2,..., 5\}
{
1
,
2
,
...
,
5
}
such that neither
A
⊆
B
A \subseteq B
A
⊆
B
nor
B
⊆
A
B \subseteq A
B
⊆
A
?
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