Solution:Marginal revenue (MR) is the additional revenue generated from selling one more unit of a good or service. When MR is positive, it means that each additional unit sold adds to the total revenue. Therefore, as output increases, total revenue continues to rise as long as MR remains positive.
Marginal revenue being zero indicates that selling one more unit does not change the total revenue. At this point, total revenue has reached its peak because any additional unit sold will not increase revenue. This is typically the point where the demand curve is unit elastic.
Negative marginal revenue means that selling an additional unit decreases total revenue.This occurs when the price reduction required to sell more units outweighs the revenue from the additional units sold. As a result, increasing output beyond this point leads to a decline in total revenue.