Mozart & Company paid cash dividends totaling $150,000 in 2013 and $75,000 in 2014. In 2015, the company will pay cash dividends of $800,000. There were no dividends in arrears as of January 1, 2013. There are 25,000 shares of common stock outstanding and 100,000 shares of 6 percent, $50 par cumulative preferred. What is the amount of cash dividends payable to common stockholders in 2015?

The answer is $125000. I want to know how to calculate.