Total revenue can be obtained by multiplying

Analyze the question: It asks how total revenue (TR) is obtained by multiplication.

Concept: Total revenue is the total amount a firm receives from selling its output.

TR = Price (P) × Quantity sold (Q)

Checking each option:

• A. Price by quantity sold: This is the standard definition of TR. Correct.
• B. Average revenue by the demand: This is not a standard formula. Average revenue is actually the same as price, and "demand" is not a number you multiply by. Wrong.
• C. Marginal revenue by marginal cost: These two are compared to find the profit-maximizing output (MR = MC), not multiplied to get revenue. Wrong.
• D. Average revenue plus marginal revenue: This uses addition, not multiplication, and has no meaning in economics. Wrong.
• E. Average cost by variable cost: These are cost concepts, so they can't give revenue. Wrong.

Example: If a Lagos trader sells 50 loaves of bread at ₦600 each: TR = ₦600 × 50 = ₦30,000

Also note that since AR = TR ÷ Q, and AR equals price, then TR = AR × Q. This is the same idea as option A.

Answer: A. Price by quantity sold

Exam tip: Remember "TR = P × Q". Revenue is about what comes in (price and quantity), and cost options (like C and E) can be eliminated at once. Also, "MR = MC" is a profit-maximizing condition, not a revenue formula.