From the following demand schedule for a monopolist, what is the marginal revenue associated with the sale of the fourth unit?
A)$10
B)$30
C)$60
D)$240
E)marginal revenue cannot be determined from the information given

Question

From the following demand schedule for a monopolist, what is the marginal revenue associated with the sale of the fourth unit? 
A)$10 
B)$30 
C)$60 
D)$240 
E)marginal revenue cannot be determined from the information given

Quizplus · Accepted Answer

The marginal revenue is calculated as the change in total revenue that results from selling one additional unit of output.

At a price of $90, the monopolist can sell 5 units. 
At a price of $80, the monopolist can sell 6 units.

So the marginal revenue from selling the fourth unit is the difference between the total revenue from selling 4 units and the total revenue from selling 3 units: 
($320 - $240) = $80

Therefore, the correct answer is B) $30.

From the Following Demand Schedule for a Monopolist, What Is