Answer:
$0.50
Explanation:
Marginal cost is the additional expense associated with consuming, selling, or producing one extra unit. For Susan, the marginal cost is the extra cost incurred by purchasing the 10th gallon of gasoline.
To obtain the marginal cost:
The cost of 9 gallons plus cash wash
=(9 x $2) + $1.50= $19.50
cost of 10 gallons plus cash wash
=(10 x $2) cash wash is free= $ 20
The extra cost associated with the additional unit (marginal cost)
= $ 20- $ 19.50
=$0.50
