if a principal is compounded annually it's becomes 4 times in 2 years, what should be the rate of growth

Suppose the principal amount to be compounded annually is Rs.P.
Time; T = 2 years
Also let the rate of growth is R.
Now, according to the question we have;
$$\begin{gathered} 4P = P{\left(1+\frac{R}{100}\right)}^2 \\ \Rightarrow 4 = {\left(\frac{100+R}{100}\right)}^2 \\ \Rightarrow 4 = \frac{{\left(100+R\right)}^2}{10000} \\ \Rightarrow 40000 = {\left(100+R\right)}^2 \\ \Rightarrow \left(100+R\right) = \sqrt{40000} \\ \Rightarrow \left(100+R\right) = 200 \\ \Rightarrow R = 200-100 = 100 \end{gathered}$$

Therefore rate of growth is 100%.