A retail company's total sales in a year were £2,710,000. The cost price of goods sold was £2,040,000. During the year the following overheads were paid (treat wages as overheads): £ Wages 198,500 Electricity and gas 15,300 Telephone 1,790 Rent of premises 41,090 Office expenses 17,030 Calculate: (a) gross profit (b) net profit (c) the total overheads as a percentage of the total sales.