Let rate of interest = $$r\%$$ Sum of Rs. 2500 amounts to Rs. 2970.25 Time period (t) = 2 years => Amount under compound interest = $$P(1+frac{R}{100})^T$$ => $$2500(1+frac{r}{100})^2=2970.25$$ => $$(1+frac{r}{100})^2=frac{2970.25}{2500}=1.1881$$ => $$1+frac{r}{100}=sqrt{1.1881}=1.09$$ => $$frac{r}{100}=1.09-1=0.09$$ => $$r=0.09 imes100=9\%$$ => Ans - (B)