The race ratio of the number of cups of blue paint to the number of cups of red paint that Laura mix to a shade of purple paint equals 3:1 part A:write a sentence to describe the number of cups of blue paint that lure mix with each tub of red paint .
Part B: how many cups are red paint should Laura add to each cup of blue paint to make the shade of purple? explain your reasoning .
Part C: if Laura purchased 6 cups of blue paint for $48 what is the unit price per cup of blue paint ?