Use the compound amount equation A = P(1 + r)^t and take as your answer the total amount after 5 years. Here the principal is $75,000, the interest rate is 0.0725 and the number of years (t) is 5:
The 4 litres of red has to be 2 parts of the mixture, so each part will be 2 litres. Therefore 3 parts of cream will be 6 litres and the one part of blue will be 2 litres.
