A sum of money is put at compound interest for 2 years. What is the rate of interest per annum?

Statement I: If the same amount of money is put at simple interest for three years then the amount of interest is Rs.600 more than the interest amount calculated on CI at the end of 2 years

Statement II: The simple interest on the same sum at the end of four years is Rs.3200

Statement III : Sum of money becomes 4 times in two years at compound interest