if there are 31 persons shake hands with each other in cyclic sequence.then how many shakehands are possible?

• any person will shake hand with 31-1=30 persons & if two persons shake hand with each other it will counted 1
  
  no. of shakehands = 31*(31-1)/2 = 31*15 = 465
• 10 years agoHelpfull: Yes(35) No(24)
• since they are in cyclic sequence the ans will be n i.e 31
• 10 years agoHelpfull: Yes(34) No(3)
• for the shake hand 2 persons is needed hence
  from 31 person
  no.of shake hands = 31c2=465
• 10 years agoHelpfull: Yes(14) No(2)
• lets take example of four
  
  a
  b c
  d
  
  so in cycle of four
  a shakes to b
  b d
  d c
  c a
  
  so 4 can shake 4 hands
  this means in cycle of 31
  31 hand shake is possible
• 10 years agoHelpfull: Yes(11) No(1)
• since, to shake hands we need 2 hands at a time. so it will be
  31c2= 31*30*29!/29!*2
  = 31*15
  ans:465
• 10 years agoHelpfull: Yes(6) No(3)
• they are in cyclic sequence so answer should be 31....
  
• 10 years agoHelpfull: Yes(5) No(0)
• as it is cyclic, i think, answer will be 31 only
• 10 years agoHelpfull: Yes(3) No(1)
• As 31 persons sit in cyclic manner there would be only 31 hand shakes.465 hand shakes are possible when they shake hands randomly with anyone.
  for ex: 4 persons A,B,C,D sitting in cyclic order can shake hands in this way
  A-B,B-C,C-D,D-A.Similarly for 31 persons it would be 31 hand shakes only.
• 9 years agoHelpfull: Yes(3) No(0)
• The first person shakes his hand with 30 persons.
  The second guy shakes his hand with 29 persons, excluding the 1st person and himself.
  The third one shakes with 28.
  So, the total number of shake hands are 30+29+28+....1
  S= n/2(a+l),
  where n=30, a=1, l=30
  S= 465
• 10 years agoHelpfull: Yes(1) No(1)
• n=31
  using this formula
  n(n-1)/2=31*(31-1)/2=31*30/2=465
  ans:465
• 9 years agoHelpfull: Yes(1) No(1)
• 31c2=465 ans
  
• 9 years agoHelpfull: Yes(1) No(0)
• since they are in cyclic sequence the ans will be n i.e 31 therefore 31c2 ans
• 9 years agoHelpfull: Yes(0) No(2)
• Total Shake hands=31c2=465
• 9 years agoHelpfull: Yes(0) No(0)