solve the last one please

A single server queuing system with a Poisson arrival rate and exponential service time has an average arrival rate of 12 customers per hour and an average service rate of 16 customers per hour. What is the probability that this system will contain 4 or more customers? a. 0.7627 b. 0.3164 c. 0.6836 d. 0.5781 Customers arrive at a video rental desk at the rate of 7 per minute(Poisson).Each server can handle 2.334 customers per minute(Poisson). If there are 6 servers, determine the probability of 5 or fewer customers in the system. a. 0.901 b. 0.017 C. 0.025 d. 0.049