A private equity firm XYZ performs a leveraged buyout in which they purchase all equity and debt of company ABC for $5 billion. XYZ finances this purchase with $1 billion of their own capital and borrows the remaining $4 billion at 20% interest. In one year (unusually short for LBO), XYZ pays off the debt and sells ABC for $7.5 billion. What is XYZ's return on their invested capital (the $1 billion)? Hint: draw a balance sheet.