Anders, Inc., has 10,000 shares of 5%, $100 par value, cumulative preferred stock and 40,000 shares of $1 par value common stock outstanding at December 31, 2013. There were no dividends declared in 2011. The board of directors declares and pays a $90,000 dividend in 2012 and in 2013. What is the amount of dividends received by the common stockholders in 2013?

a. $30,000

b. $50,000

c. $90,000

d. $0

Could you explain why we use 90000*2-50000*3? Why 3 years?