Principal (P) = Rs 8000
Rate of interest = 9% per annum or 9/2 % per half year
Number of years = 1 year
There will be 2 half years in 1 year.
A = p( 1 + R/100)n
= Rs [800 (1 + 9/200)2]
= Rs [8000 (209/200)2]
= Rs (8000 x 209/200 x 209/200) = Rs 8736.20
C.I. = A − P = Rs 8736.20 − Rs 8000 = Rs 736.20