Derby Phones is considering the Introduction of a new model of headphones with the following price and cost characteristics. Sales price Variable costs Fixed costs $ 255 per unit 125 per unit 286,000 per month Required: a. What number must Derby sell per month to break even? b. What number must Derby sell to make an operating profit of $182,000 for the month? a. Break-even sales in units b. Number of units to be sold