How many liters of each are needed to make 65 liters of this color?

Question

A certain color is made by blending red paint and blue paint in a 9:4 ratio.

Answer 1

Just like your commission example, but here you are mixing paint.

The ratio is 9 to 4 so you need to divide things into the total of 13 parts.

Find what 65 liters is when divided into 13 parts.

Then mix in 9 parts red and 4 parts blue.

 

You are doing is mixing 9/13's of 65 liters red, and 4/13's of 65 liters blue.