Everybody in the room shake hand with each other . The total no of hand shake is 66 . Then what is the total no of people in the room.
Answers
Answered by
4
Let the number pf persons be 'n'
n*(n-1)/2 = 66
n*(n-1) = 132
n*(n-1) = 12*11
Hence, n = 12 [comparing above]
No: of people in the room = 12
[formula check: Let there be 3 people namely, A, B & C. Handshakes-- A-B, A-C, B-C..3 nos. formula: 3*2/2 = 3.... Let us consider 4 people, A, B, C, D. Handshakes-- A-B, A-C, A-D, B-C, B-D, C-D..6 nos. formula: 4*3/2 = 6..verified]
Hope it helps.
n*(n-1)/2 = 66
n*(n-1) = 132
n*(n-1) = 12*11
Hence, n = 12 [comparing above]
No: of people in the room = 12
[formula check: Let there be 3 people namely, A, B & C. Handshakes-- A-B, A-C, B-C..3 nos. formula: 3*2/2 = 3.... Let us consider 4 people, A, B, C, D. Handshakes-- A-B, A-C, A-D, B-C, B-D, C-D..6 nos. formula: 4*3/2 = 6..verified]
Hope it helps.
Similar questions