3. velue 10.00 points 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 365 per unit 145 per unit 528,000 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 $220,000 for the month? Number of units sold eBook & Resources References Search the web and Windows