During 2018, Park Corporation had 50,000 shares of $10 par value common stock and 10,000 shares of 8%, $50 par value convertible preferred stock outstanding. Each share of preferred stock may be converted into three shares of common stock. Park Corporation's 2018 net income was $440,000.

a. Compute the basic earnings per share for 2018.

b. Compute the diluted earnings per share for 2018.