600 shares are purchased on the margin at the beginning of the year for $40 per share. The initial margin requirement was 55%. Interest of 10% was paid on the margin loan and no margin call was ever faced. A dividend of $2 per share is received. Calculate the annual return if:

a. The stock are sold for $45 per share at the end of the year;

b. If the stock are sold for $25 per share at the end of the year.

c. Calculate the return for (a) and (b) if the purchase had been made using cash instead of on the margin.