A router receives packets from two applications. The time between the generation of consecutivepackets of application 1 and application 2 are exponential variables with rate 1 and 2, respectively. The servicetime of the router is an exponential variable with rate . Assume 1 packet (packet A) is in the buffer (and is being served) at time 0. After tB seconds, a new packet(packet B) arrives in the buffer. Find E[tB]. Compute the average permanence time of packet B in the buffer (waiting time plus transmission). Define T as the time when the last bit of the next packet arrived in the buffer is transmitted by the router.Find E[T].