At a conference, 13 members shook hands with each other before and after the meeting. How many total member of hand shakes occurred?
At a conference, 13 members shook hands with each other before and after the meeting. How many total member of hand shakes occurred?
Explanation
To find the number of handshakes, we can use the combination formula:
nC2 = n(n-1)/2
where n is the number of members (13).
For before the meeting: 13C2 = 13(12)/2 = 78
For after the meeting: 13C2 = 13(12)/2 = 78
Total handshakes = 78 + 78 = 156