working capital problem

Friends pls help me to solve this problem........................... M ltd reqjuired to forcast its working capital for the yr 2004-05 Annual sales 65lakhs % of net profit on cost of sales 20% Average credit to allow to debtors 10week Average credit to allow to creditors 4weeks Avg stock carrying (in terms of sales required) 8weeks Add 10% to computed figures to allow for contingencies. ANS- 1604172 THANKS IN ADVANCE ( ITS URGENT) :)