Everybody in a room shakes hands with everybody else. The total number of shake hands is 66. The number of persons in the room is ……………….
A. 11
B. 12
C. 10
D. 6
Answer:B
Everybody in a room shakes hands with everybody else. The total number of shake hands is 66. The number of persons in the room is ……………….
A. 11 B. 12 C. 10 D. 6