In a single-server queuing system, = 13.9 and = 19.9. Find the probability that there are fewer than 3 customers in the system

In a single-server queuing system, λ = 13.9 and μ = 19.9. Find the probability that there are fewer than 3 customers in the system at any point in time. Note that you will need to make more than one calculation to get this answer correct. Remember to round correctly to three places beyond the decimal, the nearest thousandth.