Question

You are decorating your bedroom. To get the paint colour you want, you mix 2 parts red with 3 parts cream and 1 part blue.

Answer 1

The cream paint is 3/2 of the red, since there are three parts cream for every two parts red.  Similarly, the blue paint is 1/2 of the red.  Thus, there are 3/2*4=6 liters cream paint and 1/2*4=2 liters blue paint.