A sum of money becomes Rs.4,900 in 3 years and Rs.6,400 in 5 years on compound interest, compounded annually. Find the rate of interest p.a.

A

$$11\frac{2}{7} \%$$

B

$$12\frac{2}{7} \%$$

C

$$14\frac{2}{7} \%$$

D

$$13\frac{2}{7} \%$$