What is the compound interest for 1 year on a sum of Rs. 18000 at the annual rate of 20 percent per annum compounding half yearly?

Rs.3780

Compound interest compounded half yearly ,

So , Rate = \(\frac{20 }{2}\)% = 10%

t = 2

Compound interest = Principal × ( 1 + \(\frac{rate }{100}\) )^t - Principal

= 18000 × ( 1 + \(\frac{10 }{100}\) )²  - 18000

= 18000 × \(\frac{11 }{10}\) × \(\frac{11 }{10}\)  - 18000

= 21780 - 18000

= Rs.3780