A) Rs. 4650
B) Rs. 5650
C) Rs. 6650
D) Rs. 7660
E) None of these
Correct Answer: D
$ \therefore $ $ 33940.5=25500{{( 1+\frac{R}{100} )}^{3}} $
$ \Rightarrow $ $ \frac{33940.5}{25500}={{( 1+\frac{R}{100} )}^{3}} $
$ \Rightarrow $ $ \frac{339405}{255000}={{( 1+\frac{R}{100} )}^{3}} $
$ \Rightarrow $ $ \frac{1331}{1000}={{( 1+\frac{R}{100} )}^{3}} $
$ \Rightarrow $ $ {{( \frac{11}{10} )}^{3}}={{( 1+\frac{R}{100} )}^{3}} $
$ \Rightarrow $ $ 1+\frac{R}{100}=\frac{11}{10} $
$ \Rightarrow $ $ \frac{R}{100}=\frac{11}{10}-1=\frac{1}{10} $
$ \Rightarrow $ $ R=100\times \frac{1}{10}=10% $
$ \therefore $ $ SI=\frac{Principal\times Time\times Rate}{100} $ $ =\frac{25500\times 3\times 10}{100}=Rs.,7650 $