What is the gross profit mark-up percentage for the year ended 31 December 2020? (a) 253% (b) 72% (c) 170% (d) None of the above 4 Marks Use the following table for questions 4 and 5 Sept () Oct () Sales revenue 9,000 16,400 Gross Profit/(Loss) 3,200 (2,600) Expenses 700 580 4. Calculate the cost of sales for Sept. (a) 5,800 (b) 13,800 (c) 19,000 (d) None of the above 4 Marks 5. Calculate the net profit/ loss for October (a) 3,180 (b) (3,180) (c) 2020 (d) None of the above