A certain sum when lent at compound interest, the interest being compounded annually, amounts to Rs.1331 in 3 years and Rs. 1464.10 in 4 years. Find the rate of interest per annum.
10%
15%
25%
5%
20%
Interest in 3 year is = 1331
Interest 4 years is = 1464.10
Difference = 333.10
So rate is