The compound interest of Rs. 20480 at 6 1/ 4% per annum for 2 years 73 days is?

C.I. = Rs[20480 x(1 +25/4 x 100)² (1 + 1/5 x 25/4 x 100) - 20480 ]
= Rs.[(20480 x 17/16 x 17/16 x 81/80) - 20480]
= 20480[23409 - 20480/20480]
= Rs .2929