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Question Number 125460 by john_santu last updated on 11/Dec/20
$$\:{In}\:{a}\:{room}\:{containing}\:{N}\:{people} \\ $$ $${N}>\mathrm{3},\:{at}\:{least}\:{one}\:{person}\:{has}\:{not} \\ $$ $${shaken}\:{hands}\:{with}\:{everyone} \\ $$ $${else}\:{in}\:{the}\:{room}.\:{What}\:{is}\:{the}\: \\ $$ $${maximum}\:{number}\:{of}\:{people}\: \\ $$ $${in}\:{the}\:{room}\:{that}\:{could}\:{have}\: \\ $$ $${shaken}\:{hands}\:{with}\:{everyone}\: \\ $$ $${else}?\: \\ $$
Answered by liberty last updated on 11/Dec/20
$${N}ā\mathrm{2} \\ $$