Question

Every person at a party of Eighty-Nine people said hello to each of the other people at the party once. How many "hellos" were said at the party?​

Answer 1

3916 hellos

Step-by-step explanation:

That is the number of combinations of 2 from 89

= 89! / (89-2)! 2!

= 89! / 87! 2!

= 89*88 / 2

= 3916.

Answer 2

3916 hello's were said

Step-by-step explanation:

(n/2)(n-1)

insert n = 89

(89/2)(89-1)

(44.5)(88)

3916 hello's