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\begin{document}


\begin{center}
{\Large Puzzle 5}
\end{center}

\bigskip

Mr and Mrs Brown are having a party. They invited three other married
couples, so there are eight people present. When greeting each other, some
people shake hands with some people. Of course, nobody shakes hands with
his/her spouse. \ When Mr Brown asks the other seven people: "How many
people did you shake hands with?", he receives seven different answers. How
many people did Mrs. Brown shake hands with?

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