The ratio of the number of cups of blue paint to the number of cups of red paint that Lara mixed to make a shade of purple paint is 3.1. Part A: Write a sentence to describe the number of cups of blue paint that Lara mixed with each cup of red paint (4 points)
Part B: How many cups of red paint should Lara add to each cup of blue paint to make the shade of purple? Explain your reasoning (4 points)
Part C: I Lara purchased 6 cups of blue paint for $48, what is the unit price per cup of blue paint? (2 points)