just need help with question 1

please use excel solver to solve this problem. please help me build conceptual model for question 1

A small new bank branch is launched. The bank manager, Tom, is considering options in designing its waiting lines system. Providing good service and experience for its customers is one of important strategic goals of the bank. Currently, the bank has one teller using one window to serve customers. To evaluate the waiting lines system, Tom has collected data for a two-month period. After doing a data analysis, Tom found that averagely, 150 customers demanded the service per day. In addition, statistical analysis demonstrated that time between arrivals and service time approximately follow uniform distributions. Specifically, Tom found that time between arrivals could be 1 customer with a probability of 15%, 2 customers with a probability of 20%, 3 customers with a probability of 25%, 4 customers with a probability of 20%, 5 customers with a probability of 15%, and 6 customers with a probability of 5%; for the service time, the teller needs 2 minutes with a probability of 25%, 3 minutes with a probability of 35%, 4 minutes with a probability of 25%, and 5 minutes with a probability of 15%, to serve a customer. Tom would like to evaluate this waiting line system. Please provide the analysis to answer the following two questions. Q1: What is the average waiting time for customer in the current waiting lines system? Q2: Please provide at least three suggestions for Tom to improve its service system and explain why these suggestions can help to improve the bank's service system