A, in one day there are 6 clients and for each day multiplied it equals C for example if you were to plug in 1 for d 6(1)=6 and so on which shows the total clients.
You save 5 cents per ounce by using the 40 ounce jar, because if you do $5.20 divided by 40 it equals $0.13 but if you do $2.70 divided by 15 it equals $0.18 which is 5 more cents the the 40 ounce