Calculate the C.I. on ₹ 3500 at 6% per annum for 3 years, the interest being compounded half-yearly.

When interest is compounded half-yearly.

$\Rightarrow A = P\Big(1 + \dfrac{r}{2 \times 100}\Big)^{n \times 2} \\[1em] \Rightarrow A = 3500 \times \Big(1 + \dfrac{6}{200}\Big)^{3 \times 2} \\[1em] \Rightarrow A = 3500 \times \Big(\dfrac{206}{200}\Big)^6 \\[1em] \Rightarrow A = 3500 \times (1.03)^6 \\[1em] \Rightarrow A = 3500 \times 1.194052 \\[1em] \Rightarrow A = ₹ 4179.18$

By formula,

C.I. = A - P = ₹ 4179.18 - ₹ 3500 = ₹ 679.18

Hence, C.I. = ₹ 679.18