I can't understand your question do you have any number there?
To solve this, you divide the price by the amount of ounces, and find the one which results in the smallest number. That was B, $4.29 for 12 ounces.
Answer: The domain is all real numbers
I can't say that the y intercept is 3 because when you distribute,

It seems like the y intercept is 24.
Answer:
The answer would be 0.00000007