Answer : Option A

Explanation :

Amount after 2 year on Rs.3000 at 10% per annum when interest is compounded annually
$MF#%= \text{P}\left(1 + \dfrac{\text{R}}{100}\right)^\text{T} = 3000\left(1 + \dfrac{10}{100}\right)^2 = 3000\left(\dfrac{110}{100}\right)^2 \\\\= \dfrac{3000 \times 110 \times 110}{100 \times 100} = 3 \times 11 \times 110 = 3630$MF#%
Compound Interest = 3630 - 3000 = Rs.630
Given that simple interest on a certain sum of money for 4 years at 5% per annum is half of the compound interest.
$MF#%\text{i.e., simple interest = }\dfrac{630}{2}\text{ = Rs.315}\\\\ \text{P} = \dfrac{100 \times \text{SI}}{\text{RT}} = \dfrac{100 \times 315}{5 \times 4} = \dfrac{20 \times 315}{4} = 5 \times 315 = \text{Rs. 1575}$MF#%