RBI Assistant Mains 2017 Sitting 3 Paper

Rs. 4,800 was invested at 10 per cent per annum compound interest (compounded annually) and a certain sum was invested at 20 per cent per annum compound interest (compounded annually) .
After 2 years the total interest accrued from both the schemes was Rs. 3472. What was the sum invested at 20 per cent per annum compound interest (compound- ed annually) ?