Rs. 9000 is lent at the rate of 80 percent per annum on compound interest (compounded half yearly). What will be the compound interest of 12 months?

Correct option is D

Given:
Principal (P) = Rs. 9000
Rate of Interest (R) = 80% per annum
Time (T) = 12 months (1 year)
Formula Used:
A = P(1 + R/n)^(nt)
Compound Interest (CI) = A - P
Solution:
Half yearly rate = 80%/2 = 40%
A = 9000(1 + 40/100)2 = 17640
CI = 17640 – 9000 = 8640