Answer:
An amusement park studied methods
Step-by-step explanation:
D is the correct answer I think.
X could either be 4 or 5, depending on which x the question asks. If you have to chose one answer go with 5 because it's associated with the y.
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.