At the end of a conference, the 10 people present all shake hands with each other once. How many handshakes will there be altogether?
At the end of a conference, the 10 people present all shake hands with each other once. How many handshakes will there be altogether?
Explanation
To calculate the total number of handshakes:
Each person shakes hands with 9 others.
There are 10 people, so it seems like there would be 10 x 9 = 90 handshakes.
However, this counts each handshake twice (once for each person involved).
To correct this, divide the total by 2:
90 / 2 = 45