Question

28 shake hands were exchanged in a meeting, each person shakes hands with every other person only once.how many people were present in the meeting

Answer 1

I believe that fourteen people were present at the meeting. Since all of the people shook hands every person once, it has to be twenty eight divided by two, which would equal fourteen.

I'm not sure but I hope this helps a little.

Answer 2

Given 28 hands were shaked

according to the formula

hand shaked =
$= \frac{n(n - 1)}{2}$
Where no. of people in party is n


$28 = \frac{n(n - 1)}{2}$

56 = n² - n

n² - n - 56 = 0

n² - 8n + 7n - 56 = 0

n ( n - 8 ) + 7 ( n - 8 ) = 0

( n + 7 ) ( n - 8 ) = 0


• ( n + 7 ) = 0

n = -7 ( neglected coz no. of people can't be negative )

• ( n - 8 ) = 0

n = 8

No. of people in the party is 8 .