CSATPermutation, Combination & ProbabilityPermutation and Combination2015

In a society it is customary for friends of the same sex to hug and for friends of opposite sex to shake hands when they meet. A group of friends met in a party and there were 24 handshakes. Which one among the following numbers indicates the possible number of hugs?

A

39

B

30

C

21

D

20

Correct Answer: Option C

Explanation

Let's say the group has

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