Given,
Amount = Rs.4913
Time = 18 months \(=\frac{18}{12}\) years
\(=\frac{3}{2}\times2\) = 3 half yearly
Rate \(={12}\frac{1}{2}\text%\) \(=\frac{25}{2}\text%\)
\(=\frac{25}{4}\text%\) half yearly
Let principal = P
So,
\({A}={P}[({1}+\frac{R}{100})^T]\)
\(={P}({1}+\frac{25}{4\times100})^3]\) = 4913
\(={P}[(\frac{17}{16})^3]\) = 4913
\(={P}\times\frac{4913}{4096}\) 4913
\(={P}=\frac{4913\times4096}{4913}\) = Rs.4096
Hence ,
Principal = Rs. 4096
