Suppose that computer A sends each message to computer B simultaneously over two unreliable telephone lines. Computer B can detect when errors have occurred in either line Let the probability of message transmission error in line 1 and line 2 be q1 and q2 respectively. Computer B requests retransmissions until it receives an error-free message on either line (a) Find the probability that more than k transmissions are required (b) Find the probability that in the last transmission, the message on line 2 is received free of errors