Final answer:
When eleven people greet each other by shaking hands, a total of 55 handshakes take place.
Step-by-step explanation:
To find the number of handshakes that take place when eleven people greet each other by shaking hands, we can use a simple formula. The formula for finding the number of handshakes in a group of n people is n * (n-1) / 2. In this case, n = 11, so the number of handshakes would be 11 * (11-1) / 2 = 55.