On ₹ 6000, the difference between C.I. and S.I. in 2 years and at 10% compound interest, compounded per year, is :

1. ₹ 120

2. ₹ 600

3. ₹ 60

4. ₹ 180

For S.I. :

Principal = ₹ 6000

Rate = 10%

Time = 2 years

S.I. = $\dfrac{6000 \times 10 \times 2}{100}$ = ₹ 1200.

For C.I. :

C.I. = A - P

$= P\Big(1 + \dfrac{r}{100}\Big)^n - P \\[1em] = 6000 \times \Big(1 + \dfrac{10}{100}\Big)^2 - 6000 \\[1em] = 6000 \times \Big(\dfrac{110}{100}\Big)^2 - 6000 \\[1em] = 6000 \times \Big(\dfrac{11}{10}\Big)^2 - 6000 \\[1em] = 6000 \times \dfrac{121}{100} - 6000 \\[1em] = 7260 - 6000 \\[1em] = ₹ 1260.$

Difference between C.I. and S.I. = ₹ 1260 - ₹ 1200 = ₹ 60.

Hence, Option 3 is the correct option.