Explanation:

To calculate the total compound interest on the given amounts:

- Total Sum: Rs. 45000, divided into a ratio of 4:5.

- Small Sum (4 parts): \((4/9) \times 45000 = 20000\)

- Large Sum (5 parts): \((5/9) \times 45000 = 25000\)

- Interest on Small Sum: 10% per annum

- Compound Interest = \(20000 \times (1 + 10/100)^3 - 20000 = 6620\)

- Interest on Large Sum: 20% per annum

- Compound Interest = \(25000 \times (1 + 20/100)^3 - 25000 = 18200\)

- Total Compound Interest: \(6620 + 18200 = 24820\)

The correct option is:

- Option 2: Rs. 24820