Income before income tax liability analysis

Total current liabilities (non-interest-bearing) $450,000
Bonds payable, 6% (issued in 1982; due in 2010) 750,000
Preferred stock, 5%, 100 par 300,000
Common stock, $10 par 750,000
Premium on common stock 150, 000
Retained earnings 600,000
Income before income tax was $200,000, and income taxes were $80,000 for the current year.
Required:
Calculate each of the following:
a. Return on assets (using ending assets)
b. Return on total equity (using ending total equity)
c. Return on common equity (using ending common equity)
d. Times interest earned