A sum of ₹9000 amounts to ₹13356 at a certain rate percent per annum in $$4\frac{2}{5}$$ years at simple interest. What will be the simple interest on the same sum at double the rate for $$2\frac{1}{3}$$ years.

Given, 

Principal (P) = ₹9000

Time(t) = $$4\frac{2}{5}=\frac{22}{5}\%$$

Amount (A) = ₹13356

Interest = Amount - Principal = 13356 - 9000 = ₹4356

As we know, 

S.I = $$\frac{P\times\ R\times\ T}{100}$$

$$\therefore\ $$4356 = $$\frac{9000\times\ 22\times\ R}{100\times\ 5}$$

$$\therefore\ R=\frac{\left(4356\times5\right)}{90\times\ 22}=11\%\ $$

According to Question : 

$$SI=\ \frac{\left(9000\times\ 22\times\ \frac{7}{3}\right)}{100}=₹4620$$