Shoppers at a Piggly Wiggly store enter the store at the rate of 50 customers per hour and spend an average of 30 minutes selecting their groceries. When it comes time to check out, shoppers have their choice of two types of checkout lines; an express line for shoppers with 20 items or fewer and a single line for shoppers regardless of how many items are in their cart. About 25% of all shoppers can (and do) choose the express line. There are on average two shoppers in the express line and nine shoppers in the non-express line. Once it is their turn, it takes express checkout shoppers an average of three minutes to check out and non-express customers an average of five minutes to check out.

1) How many customers are in the Piggly Wiggly at any given time?

2) How long does each type of customer spend in the store? How long does the average customer spend in this store?