Answer
They would produce up to the point where the marginal revenue equals marginal costs.
Work Step by Step
Competition decreases the profits for businesses because they have to compete with others on price and quality. If sellers form a cartel, however, they could act as a monopoly and set the price and quantity produced as a monopoly would do.
So, they would produce up to the point where the marginal revenue equals marginal costs. This is the point where maximum profitability can be achieved.
