Tan2017 wrote:
How many guests were present at the party?
1)There were 45 handshakes if the guests shook hands with each other and every 2 guests shook hands exactly once
2)If there were half as many guests present, they could sit in a row in 120 different ways
let n be the number of guests
Stmt 1- the number of handshakes between the guests could be obtained by nC2 where we need to select 2 guests for a shake.
nC2=45. Sufficient to calculate n.
Stmt 2- (n/2) guests could be seated in a row in (n/2)! ways.
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