Treasury stock transaction, can anyone help me with this problem?

"edit EX 12-14 Treasury stock transactions Obj. 5 Mystic Lake Inc. bottles and distributes spring water. On July 9 of the current year, Mystic Lake reacquired 60,000 shares of its common stock at $42 per share. On September 22, Mystic Lake sold 45,000 of the reacquired shares at $51 per share. The remaining 15,000 shares were sold at $40 per share on November 23. a. Journalize the transactions of July 9, September 22, and November 23. b. What is the balance in Paid-In Capital from Sale of Treasury Stock on December 31 of the current year? For what reasons might Mystic Lake Inc. have purchased the treasury stock