I would say 33.. But im not 100% sure
Answer:
$1,545,000
Explanation:
The formula to compute the cost of the building equal to
Rate of return = (Rental income - expenses) ÷ (cost of building
)
where,
Rate of return = 8%
Rental income equals to
= ($600 × 4 units + $750 × 4 units + $725 × 4 units + $800 × 4 units) × 12 months
= $138,000
Total expense
= $1,200 × 12 month
= $14,400
Now the cost of building would be
8% = ($138,000 - $14,400) ÷ (cost of building
)
8% = $123,600
So, the cost of building equal to $1,545,000
Answer: B. The firm would install the filter at a cost of $ 300,000.
Explanation:
If the community owns the property rights, they would be able to demand that the firm pay the external cost of $500,000 per year.
If on the other hand the company installed a filter, it would cost them $300,000 but then they would not have to pay the community the $500,000.
The lower cost option would be to install the filter for $300,000 which is what the firm would do.
The question is incomplete. The complete question is :
A manufacturer believes that the cost function : 
approximates the dollar cost of producing x units of a product. The manu- facturer believes it cannot make a profit when the marginal cost goes beyond $210. What is the most units the manufacturer can produce and still make a profit? What is the total cost at this level of production?
Solution :
Given the cost function is :
Now, Marginal cost = 
So, if the marginal cost = $ 210, then the manufacturer also makes a profit and if it goes beyond $ 210 than the manufacturer cannot make a profit.
Therefore, we have to equate : 
So when x = 45, then C(x) = $ 8042.5
Therefore, the manufacturer 
to 45 units and 
This leads to a total cost of $ 8042.5
