If 10 boys meet at a reunion and each boy shakes hands exactly once with each of the others, then what is the total number of handshakes?
a) 10!
b) 10*10
c) 10*9
d) 45
e) None of these

• If 10 boys meet at a reunion and each boy shakes hands exactly once with each of the others
  9+8+7+6+5+4+3+2+1=45
  the total number of handshakes is 45(ans)
• 12 years agoHelpfull: Yes(18) No(2)
• answr-10C2=45
• 12 years agoHelpfull: Yes(17) No(1)
• for such type questions (when 2 people shake hands only once,there is no repetition),
  formula is -
  (n(n-1))/2
  here n=10
  so on solving, (10(10-1))/2
  (10*9)/2
  we get, 45 ans.
• 12 years agoHelpfull: Yes(13) No(2)
• If 10 boys meet at a reunion and each boy shakes hands exactly once with each of the others
  9+8+7+6+5+4+3+2+1=45
  the total number of handshakes is 45(ans)
• 12 years agoHelpfull: Yes(5) No(1)
• ANS : d) 45
  Here as each boy shakes hand with each of other , so the total number of handshakes is
  10C2 (because there is no repetition)
  == 10!/(8!*2!) = (10*9)/2 = 45
• 12 years agoHelpfull: Yes(3) No(2)
• formula is n/2(n+1)
  9/2(9+1) solve it & get 45 ans
  
• 12 years agoHelpfull: Yes(2) No(4)
• Every person shakes hand with 9 other persons but each handshake is shared between two persons.
  so total handshakes = 10*9/2=45
• 12 years agoHelpfull: Yes(2) No(0)
• 9+8+7+6+5+4+3+2+1+0=45
  n(n+1)/2=sum of seriess
  9(9+1)/2=45
• 12 years agoHelpfull: Yes(2) No(0)
• 2 boys can handshake in 2C2 ways=1 ways
  3 boys can handshake in 3C2 ways=3 ways
  similarly
  10 boys can handshake in 10C2 ways=45 ways
• 12 years agoHelpfull: Yes(2) No(0)
• ANS IS A
  
• 12 years agoHelpfull: Yes(1) No(2)
• if circular n(n-1)=10*9
  if non circular n(n-1)/2=45
• 12 years agoHelpfull: Yes(1) No(1)
• ans=45. There is a formula for such type of question that formula is n(n-1)/2.
  and given n=10 people so that total handshakes are= 10*92=45.
• 12 years agoHelpfull: Yes(1) No(0)
• 9*10/2=45
  therfore d) 45
• 12 years agoHelpfull: Yes(0) No(0)
• OPTION D.FORMULA IS N(N-1)/(2)=10*9/2=45
• 12 years agoHelpfull: Yes(0) No(0)