) At the beginning of a peace conference between two tribes,each person shook hands precisely once with every other member of his own tribe.A total of 3856 handshakes(each pair meeting counting as one handshake). After the conference each person shook hands precisely once with every person in the other tribe,a total of 3525 handshakes.How many people attended the conference?

• C(X,2)+C(Y,2)=3856
  C(X+Y,2)-c(X,2)-C(Y,2)=3525
  Solving this we get X+Y=122
• 8 years agoHelpfull: Yes(10) No(1)
• Suppose 1st clan has 5 members and the second clan has 3 members then the number of individual handshakes between the two other clans is 5x3 = 15
  
  one or both the number of people of the clan must be a prime for the assumption
  
  
  thus taking the factors of 3525 = 5 x5 x 3 x 47 , thus the total no of people = 75 +47 = 122
• 8 years agoHelpfull: Yes(6) No(17)
• Is there any mistake in question?
  is 3856 or any other value?
  put nC2=3856
  n is the no of person
  On solving n must be an integer but here n is a decimal number.
  
• 8 years agoHelpfull: Yes(4) No(1)
• Karthik what does c(x, 2) means
• 8 years agoHelpfull: Yes(0) No(0)
• C(X,2)+C(Y,2)=3856
  C(X+Y,2)-c(X,2)-C(Y,2)=3525
  Solving this we get X+Y=122
  X+Y=n
  nC2=3525+3856
  (n*n-1)/2=3525+3856=7381
  n*n-1=14762
  122*(122-1)=14762
• 8 years agoHelpfull: Yes(0) No(0)