SOLUTION: If seven matrons assembled for a meeting shake hands with one another,how many handshakes take place

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: If seven matrons assembled for a meeting shake hands with one another,how many handshakes take place      Log On


   

Question 972909: If seven matrons assembled for a meeting shake hands with one another,how many handshakes take place
Found 2 solutions by josgarithmetic, KMST:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
This is a classic problem. Look for the pattern. Start with three points around a circle and draw the connections. Increase by one point each run and repeat.

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
Since each one of the 7 shook 6 hands,
there were 6%2A7 ordered pairs of matrons shaking hands,
but those ordered pairs include each handshake counted 2 times:
as person A shaking the hand of person B, and
as person B shaking the hand of person A.
So the number of handshakes is 6%2A7%2F2=21 .