DEF Ltd. provides the following financial data:

• Total assets: $1,000,000
• Total liabilities: $300,000
• Common stock: $220,000
• Retained earnings: $200,000
• Net income: $150,000
• Total revenues: $700,000
• Total expenses: $550,000

Determine: a) Debt ratio b) Earnings per share c) Return on investment d) Asset turnover ratio