A sum of money is invested at a rate of compounded interest that is paid out yearly. In the first two years, the interest was ₹400 and ₹420 respectively. The sum is:

₹7,500 ₹9,530 ₹8,000 ₹8,765

₹8,000

Difference in interest = 420 - 400 = Rs. 20 Rate = \(\frac{ 20 }{400}\) × 100% = 5% Now, For 1st year , Interest on Sum = 400 So, 5% = 400 Sum = 100% = \(\frac{ 400 }{5}\) × 100 = Rs. 8000