can I get some help with this problem. this topic was only briefly covered in class and I am struggling to understand what to do .

1 customer 6 min. every every 3. (20 pts) Customers arrive at a two-pump gas station at an exponential rate 10 cars per hour. However, customers will only enter the station for gas if there are no more than three cars (including the two currently being attended to). Suppose that the amount time required to service is exponential with a mean of five minutes for each pump. (a) Write its transition diagram and balance equations. (b) What proportion of customers enter the station? (c) What is the average number of customers in the station? (d) What is average amount time that an entering customer spends in the station