Answer: Option B.
Explanation:
The price per ounce can be calculated as the amount of you paid divided the number of ounces that you get.
A) we have a table:
ounces price
18 $1.5
36 $3.00
54 $4.5
We can see that here we have a linear relationship. for example, the price for 18 ounces is $1.5
Then the price per ounce is:
p = $1.5/18 = $0.083
B) here we know that 15 oz cost $0.75, the price per ounce is:
p = $0.75/15 = $0.05
C) here we have 11 ounces, and the price is $2.20
then we have:
p = $2.2/11 = $0.2
Then we can conclude that the least expensive is option B.