A mini post office that is located inside the Millenia Mall has only been in operation since last year. The mini post office is manned by only one counter and is open from 10.00 am to 4.30 pm. Customers arrive at the post office according to the following probability distribution:Time between arn'val of Probability customers (minutes) 1 0.15 2 0.20 3 0.10 4 0.25 5 0.10 6 0.20 The length of service required by customers vanes according to the following probability distribution: Length of service (minutes) Probability 0.1 5 0.35 0.20 0.30 The post ofce management has decided that they should add another counter if a customer has to wait for more than 7' minutes, on average. a) Simulate the amvals of the rst 10 customers to the post ofce using the random number given. Time between arnvalofcustomers 18 B4 48 39 44 07 79 56 21 24 Length of Service time 49 56 09 22 68 39 62 97 T7 67 (12 marks) b) Find the average waiting time per customers in minutes. (1 mark) c) What is the percentage of time that the counter is busy? (1 mark) (1) Do you think that the mini post ofce should add another counter? Why? (1 mark)