Final answer:
In a perfectly competitive market, when a firm triples its output, the total revenue will exactly triple because the firm can sell all of its output at a constant market price.
Step-by-step explanation:
If a firm in a perfectly competitive market triples the quantity of output sold, then the total revenue will exactly triple. This outcome occurs because, in a perfectly competitive market, the firm is a price taker, which means it can sell an unlimited quantity of output at the market price.
Therefore, the demand curve facing the firm is perfectly elastic, and total revenue increases proportionally with the quantity sold. So, if the output triples, total revenue also triples, illustrating the concept that in perfect competition, marginal revenue equals the market price.