To make paint, you mix 1 liter of paint pigment with 3 liter of thinner. If you want to make 15 liter of paint, how many liter of thinner will you need?

I wrote
4 liters of paint = 1 liter of paint pigment and 3 liters of thinner
1 liter of paint = 0.25 liter of paint pigment and 0.75 liter of thinner
15 liter of paint= 3.75 liter of paint pigment and 11.25 liter of thinner
is the answer 11.25 liter of thinner?