Hammerhead Charters runs fishing trips out of the local port. Hammerhead charges $100 per trip for a half-day trip. Variable costs for Hammerhead total $45 per trip and the fixed costs are $13,750 per month. Hammerhead is subject to an income tax rate of 20 percent. Required: a. How many trips must Hammerhead sell to break even? b. How many trips must Hammerhead sell to earn a monthly operating profit of $11,000 after taxes