If the letters have usual meanings, the formula for finding compound interest, compounded yearly for the given time is : 2(1/2) years : 1. P(1 + r/100)^5/2 - P 2. P(1 + r/100)^5/2 3. P(1 + r/100)^2 (1 + r/200) 4. P(1 + r/100)^2 (1 + r/100) - P