10. 36 people {a1, a2… a36} meet and shake hands in a circular fashion. In other words, there are totally 36 handshakes involving the pairs, {a1, a2}, {a2, a3}, …, {a35, a36}, {a36, a1}. Then size of the smallest set of people such that the rest have shaken hands with at least one person in the set is

a) 12 -Answer
b) 11
c) 13
d) 18

• every one in the set shake hands with 2 members (ex:a1 shakes hand with a36,a2)
  if we remove one from these three,then remaining one shake hands with other one,
  hence smallest set of people possible such that rest shake hands with atleast one in the set =36/3=12
• 10 years agoHelpfull: Yes(9) No(0)
• option a.a1,a2,a3,a4,a5,a6,........if every third person is removed then the rest of the people will have hand shake once.the multiple of 3 are 12 (since 12*3=36).
  therefore the size of smallest set of people sucha that rest have hand shake atleast once is 12.
• 10 years agoHelpfull: Yes(3) No(0)
• a2 is doing handshakes with a1 and a3, so a2 should be in smallest set.. likewise a4 is doing wit a3 and a5..in 3 members one should be smallest set..
  so the ans is 36/3=12
• 10 years agoHelpfull: Yes(2) No(0)