MathDB

In a conference, mathematicians from

11

different countries participate and they have integer-valued ages between

27

and

33

years (including

27

and

33

). There is at least one mathematician from each country, and there is at least one mathematician of each possible age between

27

and

33

. Show that we can find at least five mathematicians

m_1, \ldots, m_5

such that for any

i \in \{1, \ldots, 5 \}

there are more mathematicians in the conference having the same age as

m_i

than those having the same nationality as

m_i

.
Proposed by S. Muralidharan

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