For each of the following independent situations, calculate the break-even point in units.
(a) Variable cost per unit of $3, annual fixed costs of $42750 and selling price per unit of $9.
(b) Variable costs per unit of $10, annual fixed costs of $63200 and selling price per unit of $20.
(c) Variable costs per unit of $20, annual fixed costs of $40650 and selling price of $23.