To determine the unit price for each detergent, i.e. the price per ounce, you have to divide the cost of the detergent by the number of ounces the container has.
Detergent A
Has 32 ounces
Costs $4.80
The unit price can be calculated as:
[tex]\frac{4.80}{32}=0.15[/tex]
Detergent A costs $0.15/ounce
Detergent B
Has 48 ounces
Costs $5.76
The unit price can be calculated as the quotient between the price and the amount of detergent:
[tex]\frac{5.76}{48}=0.12[/tex]
Detergent B costs $0.12/ounce
Detergent C
Has 128ounces
Costs $17.90
Calculate the unit price by dividing the price by the number of ounces of the container:
[tex]\frac{17.90}{128}=0.139\approx0.14[/tex]
Detergent C costs $0.14/ounce.
The best detergent to buy is the one that has the lower unit price, so to determine which one is it you have to compare their price per ounce.
In this case, detergent B has the lower price per ounce and thus it is the best detergent to buy.
