Katlin needs 40 ounces of light chocolate milk and 24 ounces of heavy chocolate milk.
To achieve a mixture of 64 ounces of chocolate milk with a 12% chocolate content, Katlin needs to combine light chocolate milk with a 5% chocolate content and heavy chocolate milk with a 21% chocolate content.
Let x represent the amount of light chocolate milk in ounces and y represent the amount of heavy chocolate milk in ounces. The total quantity of chocolate milk is given by x+y=64 ounces.
The equation for the chocolate content is 0.05x+0.21y=0.12Ă—64 (12% of 64 ounces).
Solving this system of equations, the solution is x=40 ounces of light chocolate milk and y=24 ounces of heavy chocolate milk. This combination ensures the desired chocolate content in the final 64-ounce mixture.