The following information relate to Jamiu & Co. Ltd for the year ended 31st March, 2006

	N
sales	12,000
opening stock	3,000
purchases	7,000
closing stock	2,000
wages	500
Transport	400
electricity	300

From the above figures, calculate (showing all workings) the

(a) cost of  goods sold.

(b) net profit percentage.

(c) rate of  turnover.