Given,

Net Profit after tax	Rs. 3,25,000
Rate of Income tax	50%
12.5% convertible debentures of Rs. 100 each	Rs. 4,00,000
Fixed assets (at cost)	Rs. 12,30,000
Depreciation up-to-date	Rs. 2,30,000
Current assets	Rs. 7,50,000
Current liabilities	Rs. 3,50,000

Return on Investment is