A bank offers 5% compound interest calculated on half-yearly basis. A customer deposits ₹ 1600 each on 1st… · ABC26GN4148

$$\begin{aligned} & \text { unt }=₹\left[1600 \times\left(1+\frac{5}{2 \times 100}\right)^{2}+1600 \times\left(1+\frac{5}{2 \times 100}\right)\right] \\ & =₹\left[1600 \times \frac{41}{40} \times \frac{41}{40}+1600 \times \frac{41}{40}\right] \\ & =₹\left[1600 \times \frac{41}{40}\left(\frac{41}{40}+1\right)\right]=₹\left(\frac{1600 \times 41 \times 81}{40 \times 40}\right) \\ & =₹ 3321 . \end{aligned}$$ ∴ C.I. $=₹(3321-3200)=₹ 121$.