need help with problem below:

Problem 3: 20 points (= 4 + 4 + 4 + 4 + 4) A customer service line is considered as a queuing system with an unlimited number of servers. Customers arrive at the service line with the rate of 1 = 40 per hour. Service times are independent exponentially distributed random variables with the expectation equal to 3 minutes. 1. Find the steady state distribution of the number of customers in the system, Am = lim P[X(t) = m], for m = 0, 1, ..., . 2. Derive the expected idle time period, E [/] in minutes. 3. Find the average queue length (L). 4. Find the expected busy time in minutes, E using the formula: E [/] + E [B] = TO. 5. Consider the departure process defined as the number (D (t) ) of customers that have their services completed by the time t. Find the expected value, E [D(2)], of the number of customers who departed from the queue within first two hours