Cost of goods sold = opening stock + net purchases – closing stock
= 30,000 + 2,00,000 – 20,000
= 2,10,000
Therefore, percentage of gross profit on cost of goods sold is 30/70 × 100
= 42.85%.
Gross profit = Rs. 2,10,000 × 30/70
= Rs. 90,000
Sales = Cost of goods sold + Gross profit
= 2,10,000 + 90,000
= 3,00,000.