Question

Allison made purple paint by mixing 3 parts red paint with 4 parts blue paint. chris has 2 fluid ounces of blue paint. to match allison's shade of purple, how much red paint should chris mix with his blue paint

Answer 1

She will need 1.5 fluid ounces of red paint. 

To do this, you set up a proportion. 4/3 = 2/x. You cross multiply and get 6 = 4x. Divide and now you know that x = 1.5, because 6/4 = 1.5.