Visa Inc. 2023 Financials:

Financial Metric	Amount
Total Revenue	$40 billion
Cost of Goods Sold	$10 billion
Operating Expenses	$15 billion
Interest Expense	$1 billion
Tax Expense	$3 billion
Total Assets	$80 billion
Total Liabilities	$30 billion

1. Calculate the operating profit margin.
2. Determine the net profit margin.
3. Compute the interest coverage ratio.
4. Determine the return on assets (ROA).