Sorry, it's long. I've tried everything to solve this, I have no clue how they got any of the MR figures, I calculated MR and I got 0.5. Help please.

* A drug company currently sells 3 million AIDS treatments in rich countries at P = $80 per treatment.
* In order to sell 6 million AIDS treatments in poor countries the drug company would have to lower price to $30 per treatment.
* Marginal cost is constant and equal to $10 per treatment in both countries.
* If the drug company cannot prevent re-sale between rich and poor countries then the marginal revenue per treatment of increasing output from 3 million (serve rich only) to 9 million (serve both rich and poor) is equal to___

a. $30 per treatment which is greater than the marginal cost of $10 per treatment and thus implies that profits will rise if the poor buyers are served.
b. $5 per treatment which is less than the marginal cost of $10 per treatment and thus implies that profits will fall if the poor buyers are served.
c. $30 per treatment which is less than the marginal revenue of $80 per treatment received from the rich buyers and thus implies that profits will fall if the poor buyers are served.
d. $30 per treatment which is greater than zero and thus implies that profits will rise if the poor buyers are served.
e. $20 per treatment which is greater than the marginal cost of $10 per treatment and thus implies that profits will rise if the poor buyers are served.

Marginal revenue is also known as Price (P). So, in rich countries MR=80. If it serves the poor countries MR=30. If it serves the poor countries with a goal of 6-million treatment and since it cannot prevent re-sale, price (MR) in the rich country also drops to 30.

Now then, MC is a constant 10. If it only serves the rich country, MR=80, meaning profit per treatment is 70. At 3-million sales, total profit becomes 210-million. If it serves both rich and poor, profit per treatment drops to 20. Total profit would be 9*20 = 180-million.

While I don't like the wording, c) seems to be the only possible correct answer.

Thanks for the help. I did end up getting the answer right, miscalculated the first couple times I did it.

MR = change in TR/ change in q
change in tr= ((9mil*30)-(3mil*80)
=270mil-240mil
=30 mil
change in q= 9mil-3mil
=6mil

MR=30/6
=$5
Since 5 is less than mc, you have gone past the profit max. point and profit will fall.

So B.

To calculate the marginal revenue (MR) per treatment of increasing output from 3 million to 9 million, you need to understand a concept called price elasticity of demand. This concept measures the responsiveness of demand to a change in price.

To get started, let's consider the demand in rich countries at the current price of $80 per treatment. Since the drug company sells 3 million treatments in rich countries, the total revenue from these sales is 3 million * $80 = $240 million.

Now, let's analyze the situation in poor countries. If the drug company wants to sell 6 million treatments in poor countries at a price of $30, we need to calculate the change in revenue from the rich countries. The change in quantity is 6 million (poor countries) - 3 million (rich countries) = 3 million treatments. The change in price is $30 - $80 = -$50 (a decrease in price).

To calculate the MR, you need to divide the change in revenue by the change in quantity.

MR = (Change in Revenue) / (Change in Quantity)

Change in Revenue = Change in Price * Quantity = -$50 * 3 million = -$150 million
Change in Quantity = 3 million

MR = (-$150 million) / (3 million) = -$50

So, based on the calculation, the MR per treatment of increasing output from 3 million to 9 million is -$50.

Now let's analyze the answer options provided:

a. $30 per treatment which is greater than the marginal cost of $10 per treatment and thus implies that profits will rise if the poor buyers are served.
b. $5 per treatment which is less than the marginal cost of $10 per treatment and thus implies that profits will fall if the poor buyers are served.
c. $30 per treatment which is less than the marginal revenue of $80 per treatment received from the rich buyers and thus implies that profits will fall if the poor buyers are served.
d. $30 per treatment which is greater than zero and thus implies that profits will rise if the poor buyers are served.
e. $20 per treatment which is greater than the marginal cost of $10 per treatment and thus implies that profits will rise if the poor buyers are served.

Based on the calculation of the MR, the correct answer is (b) $5 per treatment which is less than the marginal cost of $10 per treatment and thus implies that profits will fall if the poor buyers are served.