How many handshakes will there be between 16 people?

Question

Using another method, the number of handshakes made among 16 people. How many handshakes will there be?

Answer 1

Put the people in a line.

#1 shakes 15 hands, and is done.

#2 shakes 14 hands, and is done.

#3 shakes 13 hands, and is done.

#4 shakes 12 hands, and is done.

 

Follow this pattern.

How many hand shakes?