compute the cost of goods sold and gross profit with the help of the following information.
purchase : 3,00,000
sales : 4,00,000
purchase return : 2,000
sales return : 3,000
wages : 50,000
carriage inwards : 10,000
salaries : 25,000
stock on (1/1/2017) : 60,000
stock on (31/12/2017) : 80,000