Answer:
55 handshake
Step-by-step explanation:
Every handshake involves two people, and you can't do a handshake with yourself. There are 11 people and everyone wants to shake each other's hands. If the order important, every person will have to handshake with 10 other people before leaving.
But the order is not important for a handshake, we don't differentiate who initiate the handshake. This will follow the formula for combination. The calculation will be: 2C11= 11!/(2!9!) = 55 handshake
