JEE Main & Advanced
Mathematics
Permutations and Combinations
Question Bank
Definition of combinations, Conditional combinations, Division into groups, Derangements
question_answer
Everybody in a room shakes hand with everybody else. The total number of hand shakes is 66. The total number of persons in the room is [MNR 1991; Kurukshetra CEE 1998; Kerala (Engg.) 2001]