Correct Answer - Option 1 : 28 : 25

**Given:**

Sum of Rs. 4000 invested at rate = 10% for 2 years

Sum of Rs. 5000 invested at rate = 15% for a year

**Formula:**

Compound interest = P(1 + R/100)^{N} - P

Here, P = Principal, R = rate of interest and N = time period

**Calculation:**

Compound interest earned by A = 4000(1 + 10/100)^{2} - 4000 = Rs. 840

Compound interest earned by B = 5000(1 + 15/100) - 5000 = Rs. 750

Required ratio = 840 : 750 = 28 : 25

∴ Required ratio is 28 : 25