Question 1129724
One way is to note that 45% is 2/3 of the way between 25% and 55%, so twice as much of the 55% will be used.

Or, 
x at 25%
465-x at 55%
.25x+.55(465-x)=465*.45=209.25
.25x+255.75-.55x=209.25
-.30x=-46.50
x=155 liters
465-x=310 liters, twice as much.