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	Choose the correct choice from the following.
A) 11
B) 12
C) 13
D) 15
E) 18
if we take person a1 in the set then it will cover a36 and a2 for shaking hand.similarly if we take person a4 in the set then it will cover a5 and a3 for shaking hand and so on, so minimum 12 persons are required.   ANSWER:12
<result>B</result>
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