An airline has a marginal cost per passenger of $20 on a route from Minneapolis to Dallas. At the same time, the typical fare charged is $300. The planes that fly the route are usually full, yet the airline claims it loses money on the route. This loss may occur because

The fixed costs are too high. The marginal cost generally represents variable costs and they might be very low, but if the fixed costs are simply too high, they will need to increase the price of the plane tickets in order to break even. The break even formula is calculated by dividing total fixed costs by marginal revenue (selling price - variable costs).

forbearance of student loan payments. under forbearance, your loan payments are postponed (or reduced) but interest continues to accrue during the period of forbearance. if you don't pay the interest during that period, the interest may be “capitalized,” which means it is added to your principal balance.