Berkshire Hathaway’s financial overview as of December 31, 2023:

• Total Revenue: $400 billion
• Cost of Goods Sold: $250 billion
• Operating Expenses: $100 billion
• Interest Expense: $10 billion
• Net Income: $30 billion
• Total Assets: $700 billion
• Shareholders’ Equity: $300 billion

Determine:

1. Gross Profit Margin.
2. Operating Profit Margin.
3. Net Profit Margin.
4. Interest Coverage Ratio.
5. Return on Equity (ROE).