Question 1009366
This might be inconsistent with the intention of the exercise, but the ratios can be changed into percents of milk.

First container, 44.44 percent
Second container, 83.33333 percent
WANTED, 55.56%


(or this could be done using ordinary fractions)


The units of measure are not given, but just assume any general units you want.

x for first container to use , y for how much of the second container;
{{{system(x+y=100,44.44x+83.33y=100*55.56)}}}


{{{44.44x+83.33y=5556}}}
{{{44.44x+83.33(100-x)=5556}}}
{{{44.44x+8333-83.33x=5556}}}
{{{44.44x-83.33x=5556-8333}}}
{{{38.89x=2777}}}
{{{highlight(x=71.407)}}}, units to take from container 1
from the x value found,
{{{highlight(y=28.59)}}}, units to take from container 2


Find further that {{{x/y=2.5}}}  NOT exactly, but very nearly so.  This is like {{{highlight(highlight(x/y=5/2))}}}.
You could do the whole solution process using ordinary fractions, numerator denominator type, and get the same thing.