A firm reported $250 million in total assets and $140 in debt. It had no interest-bearing its assets. In the income statement it reported $ 560 million in sales. The firm's 80 million shares traded at $7 each. Calculate securities among

a . The price-to-book ratio (P/B)

b . The unlevered price-to-sales ratio (P/S) c . The enterprise price - to- book ratio