N people shake hands in a meeting.If there are 36 handshakes overall find value of n

Question

Combination ques

Answer 1

the handshake problem is ancient

Answer 2

if there are 2 people there is 1 handshake

if there are 3 people there are 3 handshakes

if there are 4 people there are 6 handshakes

5 people, 10 handshakes

6 people, 15 handshakes 

you should see the pattern by now

7 people, 21 handshakes

8 people, 28 handshakes

9 people, 36 handshakes answer

or, you could do the following...

0+1=1

0+1+2=3

0+1+2+3=6

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0+1+2+3+4+5+6+7+8=36

if there are 9 people, the first person shakes 8 hands

the second person shakes 7 hands

the third person shakes 6 hands

and so on...

8+7+6+5+4+3+2+1+0=36