According to the balance sheet of Ralk Inc., they have a total of $60 million in long-term debt, whose market value is $40 million. The balance sheet also reports that the company has $50 million worth of common equity and $10 million in preferred equity. Given their current prices, the market value of common equity is $100 million and the market value of preferred equity is $20 mil. What is the book value weight of its common equity?