Understanding Opportunity Cost

Question). SE is working in a hedge fund in New York, earning around 200000 per year. She is deciding to open a ESG advisory and consulting company. She estimates that she will need to provide an investment of 70,000 per year in leasing office space, with salaries of 120000 per year for two employees. Over and above, she estimates that she will need at least in overheads of about 30,000 per year. SE will use her savings with interest rate at 4% per annum. Using the above information, create a cost analysis using economist and accounting standards. Use the concept of opportunity cost, fixed and variable cost.   (The middle Road)

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Question). A commercial fisherman notices the following relationship between hours spent on fishing and the quantity of fish caught. Question from Principles of Microeconomics Gregory Mankiw.