The compound interest on a sum off ₹8,400 in 3 years at a certain rate per cent per annum, is ₹6115.20, interest being
compounded annually. What will be the difference (in ₹) between compound interest on the same sum at the same rate for $$1\frac{1}{2}$$ years, when the interest is compounded half yearly and the simple interest on the same sum for same rate and for the same period?

A

275.75

B

320.25

C

260.40

D

250