P/E ratio

Rite plc has issued share capital of $145000 comprising of 90000 equity shares of 50cents each and $100 000 10% redemeble preference shares. for the year ended 30 November 2015 profit before tax was $14 400 and profit after tax was $10 800on 30 November
2015, rite plc’s mid-market share equity share price was 84cents

What is the P/E ratio? Answer given in opentution chapter mcq’s is 7.00x..my question is why preference dividend is not deducted from earnings(10800-10000) while calculating EPS portion???