20 men handshake with each other without repetition. What is the total number of handshakes made?
a) 190 b) 210 c) 150 d) 250

• 190
  1+2+3+.....+19 =19*20/2=190
• 13 years agoHelpfull: Yes(68) No(11)
• 20c2=190
  for one hand shake we require two persons.so there 20 persons we get 190 handshakes.
• 9 years agoHelpfull: Yes(16) No(2)
• In any this type of ques do as per the mention below:
  n persons handshake with repetition=total no of handshakes n(n-1).
  n persons handshake without repetition=total no of handshakes (n-1).
  
• 12 years agoHelpfull: Yes(14) No(26)
• 1st person makes 19 handshakes.
  2nd person makes 18 hanshakes(as he had already done with 1st person).
  3rd person makes 17 handshakes.
  So on...
  Ans=19+18+17+...1=n(n+1)/2=19(19+1)/2=190
• 8 years agoHelpfull: Yes(7) No(0)
• ans:190
  for handshake one hand for each person is needed i.e 2
  2 out of 20 men i.e 20C2= 20*19/2*1=190
• 9 years agoHelpfull: Yes(2) No(0)
• n(n-1)/2 is no of handshakes in this n is 20 so 20(20-1)/2=190 is answer.
• 9 years agoHelpfull: Yes(2) No(0)
• selection of two among 20 people 20C2 = 190
• 9 years agoHelpfull: Yes(2) No(0)
• no of handshakes without repetition=19+18+17+16+15+14+13+12+11+10+9+8+7+6+5+4+3+2+1=190
• 9 years agoHelpfull: Yes(1) No(1)
• option a is correct.
  
  explanation : 20C2 = 20x19/2 =190
• 8 years agoHelpfull: Yes(1) No(0)
• correct formula
  
  total handshake=n(n-1)/2
• 8 years agoHelpfull: Yes(0) No(1)
• 190
  19+18+17+16+15+14+13+12+11+10+9+8+7+6+5+4+3+2+1=190
• 8 years agoHelpfull: Yes(0) No(2)
• 19+18+......................+2+1=190
• 8 years agoHelpfull: Yes(0) No(0)
• n(n+1)/2=190
• 8 years agoHelpfull: Yes(0) No(2)
• Given that number of men is 20. For each handshake, 2 persons are required. so 20 = n+1
  Total number of handshakes = (n*(n+1)) / 2 = 19 * 20 / 2 = 190
• 7 years agoHelpfull: Yes(0) No(0)
• used formula n(n+1)/2
  summation of 19+18+17+16+.........+1
  =190
• 7 years agoHelpfull: Yes(0) No(0)
• for every 100 19 digits have 2...bcoz we r counting the nmbr of digits hving,not the nmbr of 2's in 100(here 22,122 these digits will be counted as 1 not 2)..so answr is ((10*19)+100)/1100.as 200 to 299 there are 100 digits having 2.dats why its 10*19+100
• 7 years agoHelpfull: Yes(0) No(0)
• hanshake=nc2=20c2=190
• 6 years agoHelpfull: Yes(0) No(0)
• 2oc2=20*19/2*1
  so..answer is 190
• 6 years agoHelpfull: Yes(0) No(0)
• n(n+1)/2 = 20(21)/2 = 210
• 5 years agoHelpfull: Yes(0) No(0)
• 20C2 =190.
• 4 years agoHelpfull: Yes(0) No(0)