Answer:
the marginal revenue from selling the fifth unit is
$25
Explanation:
Perfect competition is market structure in which the following information:
All firms sell an identical product .
All firms are price takers , cannot influence the market price .
Market share has no influence on prices.
Buyers have complete informationabout the product being sold and the prices .
Resources for such a labor are perfectly mobile.
Firms can enter or exit the market without cost