Answer : Option B

Explanation :

Amount after 1 year on Rs.2400 at 10% per annum when interest is reckoned half-yearly
$MF#%= \text{P}\left(1 + \dfrac{\text{(R/2)}}{100}\right)^\text{2T} = 2400\left(1 + \dfrac{(10/2)}{100}\right)^{2 \times 1}= 2400\left(1 + \dfrac{5}{100}\right)^2= 2400\left(\dfrac{105}{100}\right)^2 \\\\= \dfrac{2400 \times 105 \times 105}{100 \times 100} =\dfrac{24 \times 105 \times 105}{100} = \dfrac{24 \times 21 \times 105}{20}= \dfrac{24 \times 21 \times 21}{4} = 6 \times 21 \times 21 = 2646$MF#%
Compound Interest = 2646 - 2400 = Rs. 246
Simple Interest on Rs.2400 at 10% per annum for 1 year
$MF#%= \dfrac{\text{PRT}}{100} = \dfrac{2400 \times 10 \times 1}{100} = \text{Rs. }240$MF#%
Required difference = 246 - 240 = Rs.6