Gallons of milk at a local grocery store are priced at one for $4.00, or two for $6.00. The marginal cost of buying a second gallon of milk:
A)equals $6.00.
B)equals $4.00.
C)equals $3.00.
D)equals $2.00.

Question

Gallons of milk at a local grocery store are priced at one for $4.00, or two for $6.00. The marginal cost of buying a second gallon of milk:
A)​equals $6.00.
B)​equals $4.00.
C)​equals $3.00.
D)​equals $2.00.

Quizplus · Accepted Answer

The marginal cost of buying a second gallon is the additional cost incurred when purchasing the second gallon. Since two gallons cost $6.00 and one gallon costs $4.00, the marginal cost of the second gallon is $6.00 - $4.00 = $2.00.

Gallons of Milk at a Local Grocery Store Are Priced