October 2018 - Math Problem

If there were 8 people at a party and everyone shook everyone else's hand exactly once, how many handshakes would there be in total?

    Solution:

    ​Number of People Who Have Arrived ​Number of Handshakes
    ​0​0
    ​2​1
    ​33​
    ​46​
    ​510​
    ​615​
    ​7​21
    ​8​28


    How many handshakes would there be if there were 10 people? What about 100 people?
     

    Department