Ateam of 12 technicians is in a meeting. at the end of the meeting each person gives each other a high five. how many high fives are given

If n technicians give high five to all the other technicians, then the number of high fives each technician gives is (n-1), but each time a technician gives a high five, the other, the receiver of the action, also gives a high five; therefore the number of high fives will be: 
Where n is the number of technicians.

Now, we can substitute the value to get out


We can conclude that at the end of the meeting 66 high fives were given.