Consider a pool of six I/O buffers. Assume that any buffer is just as likely to be available or occupied as any other. Compute the probabilities associated with the following events:

A = At least two but no more than five buffers occupied.

B = At least three but no more than five buffers occupied.

C = All buffers available or an even number of buffers occupied.

D = At least one of the events A, B, and C occurs.