(c) Rs 500
Let the sum be Rs x. Then
x\(\Big[\big(1+\frac{10}{100}\big)^2-1\Big]\) = 525
\(\Rightarrow\) x\(\Big[\big(\frac{11}{10}\big)^2-1\Big]\) = 525
\(\Rightarrow\) x\(\Big[\frac{121-100}{100}\Big]\) = 525
\(\Rightarrow\) x = \(\frac{525\times100}{21}\) = Rs 2500
For S.I.
P = Rs 2500, R = 5% p.a. and T = 4 years
Then, S.I = Rs \(\big(\frac{2500\times5\times4}{100}\big)\) = Rs 500