A man invests ₹ 9,600 at 10% per annum compound interest for 3 years. Calculate:

(i) the interest for the first year.

(ii) the amount at the end of the first year.

(iii) the interest for the second year.

(iv) the interest for the third year.

(i) For 1st year:

P = ₹ 9,600

R = 10%

T = 1 year

$\text{Interest} = \Big(\dfrac{P \times R \times T}{100}\Big)\\[1em] = ₹ \Big(\dfrac{9,600 \times 10 \times 1}{100}\Big)\\[1em] = ₹ \dfrac{96,000}{100}\\[1em] = ₹ 960$

Hence, interest for first year = ₹ 960.

(ii)

$\text{Amount = P + Interest}\\[1em] = ₹ 9,600 + 960\\[1em] = ₹ 10,560$

So, amount at the end of the first year = ₹ 10,560.

(iii) For 2nd year:

P = ₹ 10,560

R = 10%

T = 1 year

$\text{Interest} = \Big(\dfrac{P \times R \times T}{100}\Big)\\[1em] = ₹ \Big(\dfrac{10,560 \times 10 \times 1}{100}\Big)\\[1em] = ₹ \dfrac{1,05,600}{100}\\[1em] = ₹ 1,056$

Hence, interest for the second year = ₹ 1,056.

(iv)

$\text{Amount at end of 2nd year = P + Interest}\\[1em] = ₹ 10,560 + 1,056\\[1em] = ₹ 11,616$

For 3rd year:

P = ₹ 11,616

R = 10%

T = 1 year

$\text{Interest} = \Big(\dfrac{P \times R \times T}{100}\Big)\\[1em] = ₹ \Big(\dfrac{11,616 \times 10 \times 1}{100}\Big)\\[1em] = ₹ \dfrac{1,16,160}{100}\\[1em] = ₹ 1,161.60$

Hence, interest for the third year = ₹ 1,161.60.