Cost of goods sold = Net sales – Gross profit
= 7,70,000 – 3,90,000
= ₹ 3,80,000
Operating expenses = Adm. exp. + Selling and Distribution expenses
= 50,000 + 60,000
= ₹ 1,10,000
Operating ratio = \(\frac{Cost\,of\,goods\,sold\,+\,Operating\,expense}{Net\,sales}\times100\)
= \(\frac{3,80,000\,+\,1,10,000}{7,70,000}\times100\)
= \(\frac{4,90,000}{7,70,000}\times100\)
= 63.64%