Assume that there are only two stations on the Ethernet, Alice and Bob, and CSMA$/$CD

is adopted to allow multiple access. Both Alice and Bob have a steady queue of frames

to transmit. Both Alice and Bob attempt to send a frame, and suppose that the frame

collides and Alice wins the first backoff race. At the end of Alice's transmission, both

Alice and Bob attempt to transmit and collide again. The probability that Bob wins the

second backoff race is

$.(4\%)$