Sun Corporation received a charter that authorized the issuance of 100,000 shares of $10 par common stock and 50,000 shares of $50 par, 5 percent cumulative preferred stock. Sun Corporation completed the following transactions during its first two years of operation.

Year 1
Jan. 5 Sold 6,000 shares of the $10 par common stock for $15 per share. 12 Sold 1,000 shares of the 5 percent preferred stock for $55 per share.
Apr. 5 Sold 30,000 shares of the $10 par common stock for $21 per share.
Dec. 31 During the year, earned $150,000 in cash revenue and paid $88,000 for cash operating expenses.
31 Declared the cash dividend on the outstanding shares of preferred stock for Year 1. The dividend will be paid on February 15 to stockholders of record on January 10, Year 2.

Year 2
Feb. 15 Paid the cash dividend declared on December 31, Year 1.
Mar. 3 Sold 15,000 shares of the $50 par preferred stock for $53 per share.
May 5 Purchased 900 shares of the common stock as treasury stock at $24 per share.
Dec. 31 During the year, earned $210,000 in cash revenues and paid $98,000 for cash operating expenses.
31 Declared the annual dividend on the preferred stock and a $0.50 per share dividend on the common stock.

Required
a. Organize the transaction data in accounts under an accounting equation.
b. Prepare the balance sheets at December 31, Year 1 and Year 2.
c. What is the number of common shares outstanding at the end of Year 1? At the end of Year 2? How many common shares had been issued at the end of Year 1? At the end of Year 2? Explain any differences between issued and outstanding common shares for Year 1 and for Year 2.