A key assumption of the supply and demand model is that: firms will continue to raise prices until profits become positive. each firm produces at a level of output at which price exceeds marginal cost. each firm's good is unique and cannot be duplicated by other firms in the market. each firm in the market produces an identical good.

Stella company sells only two products, product a and product b. product a product b total selling price $50 $30 variable cost per unit $20 $10 total fixed costs $2,110,000 stella sells two units of product a for each unit it sells of product b. stella faces a tax rate of 40%. stella desires a net afterminustax income of $54,000. the breakeven point in units would be