When interest is compounded half-yearly then the formula for C.I. for the given time is : 1(1/2) years 1. P(1 + r/200)^3/2 - P 2. P( 1+ r/200)^3 - P 3. P(1 + r/100)^3 - P 4. P(1 + r/100)^3/2 - P