Handshake Problem Simple Formula and Practice Problem

"Hand Shake Problem" is a very common question in many competitive exams such as CSIR in the Aptitude part questions. Here we are discussing a simple formula for answering this question.

Watch this two minute video or refer the questions below

Practice Problems

1. In a group of 11 persons, each shakes hand with every other once and only once. What is the total number of such handshakes? (CSIR DEC, 2018)

This is the formula

Answer: Total No of hand shakes (T)= n(n-1)/2

                                No of persons n=11

N=11 (11-1)/2

=11x10/2=110/2
Answer: 55 handshakes

2. If there are 10 football teams in a tournament, how many games must be played in order for each team to play every other team exactly once? (same pattern question in a different context)

Answer: No of games= n(n-1)/2

N=10 (10-1)/2

=10x9/2=90/2=45 games

Use this formula for answering any questions of this pattern

Thank you so much and best wishes for your exam