1 quart = 1/4 gallon
1/3 of this is antifreeze = (1/3)(1/4) = 1/12 gallon
And 2/3 is water......so (2/3)(1/4) = 1/6 gallon
And the half-gallon contains 3/4 antifreeze = (1/2)((3/4) = 3/8 gallon
And the half-gallon contains (1/4) water = (1/2)(1/4) = 1/8 gallon
So...the ratio of antifreeze to water is [ 1/12 + 3/8] / [1/6 + 1/8] = [11/24] / [14/48] = [22 / 14 ] = [11/ 7] or 11 : 7
