Subject
Quantitative Aptitude
Topic
Permutation & Combination
Everybody in a room shakes hands with everybody else. The total number of hand-shakes is 55. The total number of persons in the room is:
Everybody in a room shakes hands with everybody else. The total number of hand-shakes is 55. The total number of persons in the room is:
ক)
11খ)
12গ)
8ঘ)
14ঙ)
None of theseExplanation
Let the total number of person be N ∵ Total number of hand-shakes is 55 ∵ For a hand shake we require two people, total number of handshake is NC2 ∴ n C 2 = 55 ∴ N = 11 personsRelated questions
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