A communications system consists of two transmitters and receivers. The transmitters transmit bytes consisting of 8 independent bits, which can each be a 0 or a 1.In Transmitter A, the probability that a bit is a 1 is 0.5.While in Transmitter B, the probability that a bit is a 1 is 0.8.Transmitter A sends three times as many bytes as Transmitter B.The receiver receives bytes from both transmitters.

a.Calculate the probability that a received byte has exactly five 1's.

b.If a byte has exactly five 1's, what is the probability that it was sent from Transmitter B?