A deli sells small, medium, and large box lunches. Each can of soda costs $1 and each bag of chips costs $1. Each sandwich costs s dollars. Some customers buy box lunches, and some customers buy items separately. Duff buys 3 medium box lunches. These box lunches do not include soda. His total cost is 3(2s + 3). How many sandwiches and how many bags of chips are in each medium box lunch that Duff buys?