Question 771209
EDIT: Corrected wording in the second sentence.


Another way to handle this is change each ratio to fraction format, and find equivalent fractions based on common (lowest is best) denominator.  The numerator is for parts milk and denominator is for TOTAL parts MILK AND water.


1:5 is {{{1/6}}}, and 3:5 is {{{3/8}}}.  Let's use denominator of 2*2*2*3=24.

{{{(1/6)*(4/4)=4/24}}} and {{{(3/8)*(3/3)=9/24}}}


Taking the same quantity of each solution, call it Q you have 2Q solution.

{{{(4/24)Q+(9/24)Q=(13/24)Q}}}  indicating how much milk is the resulting solution; but this is all contained in 2Q solution.

{{{((13/24)Q)/(2Q)=highlight(13/48)}}}, the actual fraction as milk.


You can put the ratio into the form with the colon if desired.  The 13/48 means 48 total parts, but 13 of those parts are milk, and the others are water.  You have 48-13=35 parts being just the water.
Ratio of the resulting solution is then 13:35.