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 answer:

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