Given,
Principal = Rs.64000
Time = 1 year = 1×4 = 4 quarters
Rate \(={10\text%}\)
\(=\frac{10}{4}=\frac{5}{2}\text%\)quarterly
Hence,
Compound interest
\(={P}[({1}+\frac{R}{100})^T-{1}]\)
\(={64000}[({1}+\frac{5}{200})^4-{1}]\)
\(={64000}[(\frac{41}{40})^4-{1}]\)
\(={64000}\times\frac{265761}{2560000}\) =Rs. 6644.03