AP Microeconomics Quiz: Profit Maximization

What this quiz covers

This quiz focuses on Profit Maximization, giving you a quick way to practice the rules, question types, and explanations that matter most for AP Microeconomics.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. $300$
2. $500$ (correct answer)
3. $800$
4. $2000$

Explanation: Economic profit is calculated as (Price - Average Total Cost) * Quantity. In this case, profit per unit is $20 -$15 = $5$. Total economic profit is the profit per unit multiplied by the quantity, which is $$5 * 100 = $500.

Question 2

1. only fixed costs, whereas revenue maximization considers only variable costs.
2. both revenue and costs, whereas revenue maximization considers only revenue. (correct answer)
3. only long-run outcomes, whereas revenue maximization focuses on the short run.
4. only marginal revenue, whereas revenue maximization focuses on average revenue.

Explanation: Profit is defined as Total Revenue minus Total Cost. Therefore, to maximize profit, a firm must account for its costs of production. Revenue maximization, by contrast, only seeks the output level that generates the most sales revenue, ignoring the costs incurred to produce that output.

Question 3

1. marginal revenue equals price.
2. average total cost is minimized. (correct answer)
3. total revenue equals total cost.
4. price equals marginal cost.

Explanation: Productive efficiency occurs when a good is produced at the lowest possible cost per unit. This is represented graphically as the minimum point on the average total cost (ATC) curve. While firms may not produce here in the short run, competition forces them to this point in long-run equilibrium.

Question 4

1. whether price covers average variable cost, while the exit decision is based on whether price covers average total cost. (correct answer)
2. the level of economic profit, while the exit decision is based on the level of accounting profit.
3. total revenue and total cost, while the exit decision is based on marginal revenue and marginal cost.
4. market demand, while the exit decision is based on the firm's supply curve.

Explanation: In the short run, a firm must pay its fixed costs regardless of production, so it will operate as long as price covers variable costs. In the long run, all costs are variable, so the firm will exit the industry if it cannot cover all of its costs, which are represented by the average total cost.

Question 5

1. Positive economic profits and allocative inefficiency.
2. Zero economic profit and productive efficiency. (correct answer)
3. Negative economic profits and productive inefficiency.
4. Zero economic profit but allocative inefficiency.

Explanation: In long-run equilibrium, entry and exit of firms drive the market price to the minimum of the average total cost (ATC) curve. At this point, P = MC = min ATC. The condition P = min ATC ensures zero economic profit (a normal profit) and productive efficiency. The condition P = MC ensures allocative efficiency.

Question 6

1. total fixed cost and quantity produced.
2. marginal revenue and quantity produced. (correct answer)
3. marginal cost curve and its supply.
4. average fixed cost but not its price.

Explanation: An increase in market demand will increase the market price. For a perfectly competitive firm, price equals marginal revenue. Facing a higher marginal revenue, the firm will increase its quantity produced to the new point where P = MC, thus maximizing its profit at a higher level of output.

Question 7

1. increase production to spread fixed costs over more units.
2. maintain current production since average cost is below price.
3. decrease production. (correct answer)
4. continue producing 500 widgets, as it is making a profit.

Explanation: The firm is producing where its marginal cost ($6$) is greater than its marginal revenue (the market price of $5$). This means the last unit produced cost more to make than it generated in revenue, thus reducing overall profit. The firm should decrease production to a level where price equals marginal cost.

Question 8

1. Output will increase, and profit will increase.
2. Output will decrease, and the firm will incur an economic loss. (correct answer)
3. Output will remain the same, but the firm will incur an economic loss.
4. Output will decrease, and profit will remain zero.

Explanation: A per-unit tax is a variable cost, which shifts the firm's marginal cost and average total cost curves upward. Since the market price (marginal revenue) remains unchanged in the short run, the firm will reduce its output to the new, lower quantity where P = MC'. At this new quantity, the higher ATC will be above the price, resulting in an economic loss.

Question 9

1. price equals marginal cost. (correct answer)
2. price equals average variable cost.
3. total revenue equals total cost.
4. price equals average total cost.

Explanation: In a perfectly competitive market, firms are price takers, meaning they face a perfectly elastic demand curve at the market price. Therefore, the price (P) is equal to the marginal revenue (MR) for every unit sold. Substituting P for MR in the general profit-maximization rule (MR = MC) gives P = MC.

Question 10

1. increase its output. (correct answer)
2. decrease its output.
3. maintain its current output.
4. shut down production immediately.

Explanation: The firm's marginal revenue is the market price of $10$. Since marginal revenue ($10$) is greater than marginal cost ($8$), the firm can increase its profit by producing and selling more units. It should continue to increase output until marginal cost rises to equal the market price.

Question 11

1. less than its average variable cost. (correct answer)
2. less than its average total cost.
3. equal to its marginal cost.
4. greater than its marginal revenue.

Explanation: The shutdown rule states that a firm should cease production in the short run if the revenue it receives from selling its output (the price) is not sufficient to cover its variable costs of production. If P < AVC, the firm's loss per unit is greater than its fixed cost per unit, so it minimizes losses by shutting down and only incurring fixed costs.

Question 12

1. earning a positive economic profit.
2. incurring a loss and should exit the market in the long run.
3. earning a normal profit, also known as zero economic profit. (correct answer)
4. producing at a quantity less than the productively efficient level.

Explanation: Economic profit is total revenue minus total economic cost (which includes implicit costs). If these two are equal, economic profit is zero. This is also known as a normal profit, which is the minimum level of profit needed for a company to remain competitive in the market.

Question 13

1. The market price of the good.
2. The firm's fixed costs. (correct answer)
3. The wages paid to its workers.
4. The cost of raw materials used in production.

Explanation: The profit-maximizing quantity is determined by the intersection of marginal revenue (price) and marginal cost. Fixed costs do not affect marginal cost, as marginal cost is the change in total cost from producing one more unit. Therefore, a change in fixed costs will affect the firm's profit or loss, but not the quantity it chooses to produce.

Question 14

1. Market price is greater than average total cost.
2. Market price is between its average variable cost and its average total cost. (correct answer)
3. Market price is less than its average variable cost.
4. Other firms will enter the industry, attracted by the low prices.

Explanation: The firm operates in the short run as long as the price covers its average variable costs (P ≥ AVC). If it is making an economic loss, the price must be below its average total cost (P < ATC). Combining these two conditions means the price must be between AVC and ATC.

Question 15

1. price is greater than average total cost.
2. marginal revenue is greater than marginal cost.
3. price is equal to the minimum of its long-run average total cost. (correct answer)
4. total revenue is at its maximum possible level.

Explanation: Zero economic profit is the defining characteristic of a perfectly competitive market in long-run equilibrium. This occurs when free entry and exit have adjusted the market price so that it is exactly equal to the lowest possible average total cost for each firm.

Question 16

1. average total cost curve above the minimum average variable cost.
2. marginal cost curve above its minimum average variable cost. (correct answer)
3. average variable cost curve above its marginal cost curve.
4. entire marginal cost curve.

Explanation: A firm's supply curve shows the quantity it is willing to produce at various prices. A profit-maximizing competitive firm produces where P = MC. However, if the price falls below the minimum average variable cost, the firm will shut down and produce nothing. Therefore, its supply curve is the portion of its marginal cost curve that lies above the shutdown point (min AVC).

Question 17

1. A profit of $500$
2. A loss of $100$
3. A profit of $400$ (correct answer)
4. Zero economic profit

Explanation: The profit-maximizing quantity is 50 units, where P=MC=$40$. Total Revenue (TR) is P*Q = \$40 * 50 = $2000. Total Variable Cost (TVC) is AVC*Q = $30 * 50 = $1500. Total Cost (TC) is TFC + TVC = $100 + 1500 = $1600. Profit is TR - TC = $2000 - $$1600 = $400.

Question 18

1. Price is equal to average total cost.
2. Price is less than average total cost but greater than average variable cost.
3. Price is greater than average total cost. (correct answer)
4. Marginal cost is at its minimum point.

Explanation: Positive economic profit occurs when total revenue exceeds total economic cost. On a per-unit basis, this means the price (average revenue) must be greater than the average total cost at the profit-maximizing level of output.

Question 19

1. total revenue is maximized.
2. average total cost is minimized.
3. marginal revenue equals marginal cost. (correct answer)
4. price equals average total cost.

Explanation: The universal rule for profit maximization is to produce at the quantity where the revenue from the last unit sold (marginal revenue) is equal to the cost of producing that last unit (marginal cost). Producing more would mean MC > MR, reducing profit, while producing less would mean MR > MC, forgoing potential profit.

Question 20

1. Total revenue is $1,000$, explicit costs are $600$, and implicit costs are $300$.
2. Total revenue is $1,000$, explicit costs are $600$, and implicit costs are $400$. (correct answer)
3. Total revenue is $1,000$, explicit costs are $1,000$, and implicit costs are $200$.
4. Total revenue is $1,000$, explicit costs are $1,200$, and implicit costs are $0$.

Explanation: Economic profit is Total Revenue - (Explicit Costs + Implicit Costs). Normal profit is equivalent to zero economic profit. In this case, $1,000 - ($600 + 400) = $1,000 - 1,000 = $0$. The firm is covering all of its costs, including the opportunity costs of its resources.