Question

How many handshakes can there be if there are 15 people, and everyone must shake hands with every other person once only?

Answer 1

just imagine the 15 people standing in a line.
then one person leaves the lines, shakes hands with the rest, and then leaves.
then the next person does the same.
carry on with this process to calculate how many handshakes there will be.

Answer 2

I think you do n-1/n!

Answer 3

i can not explain it any better but just interpret it...15 people wouldve shook 15 people each.

Answer 4

so (15-1)/(15!) which is just another way of saying what asnaseer said you know how to take factorial?

Answer 5

how many handshakes will the 1st person make?

Answer 6

Okay thanks guys! I get it now! :D

Answer 7

yw