At the end of a business conference the ten people present all shake hands with each other once. How many handshakes will there be altogether ?
A
20
B
45
C
55
D
90
Correct Answer: 45
Clearly, total number of handshakes = (9+ 8 + 7 + 6 + 5 + 4 + 3 + 2+1) = 45.