Vijay obtains a loan of 64000 against his fixed deposits. If the rate of interest be 2.5 paise per rupee per annum. Calculate the compound interest payable after 3 years?

P = Rs. 64000
r = 2.5 paise per rupee per annum (given)
= 0.025 rupee per rupee per annum
= 0.025 x 100 rupee per hundred rupee per annum
= 0.025 x 100 per cent per annum
= 2.5 per cent per annum
t = 3 years
C.I. = 6400[(1 + 2.5/100)³ - 1]
= 64000[(1.025)³ - 1]
= 64000[1.0769 - 1]
= 64000 x 0.0769
= 4921.6
= Rs. 4921
∴ The compound interest payable is Rs. 4921.