A)Greg mixed 2 cups of yellow paint for each cup of blue paint.
B) The ratio of yellow to blue is 2:1 = 2/1. So, if for 2 yellow is 1 blue, then for 1 yellow is x:
2/1 = 1/x
x = (1*1) / 2
x = 1/2
For each cup of yellow paint, Greg should add 1/2 cup of blue paint.
C)If 6 cups cost $54, then 1 cup cost:
54 / 6 = 9
The price per cup of yellow paint is $9.