Question 235012
In words:
(total liters of pure)/(total liters) = 60%
Let {{{x}}} = liters of pure (100%) antifreeze to be added
{{{(x + .4*12)/(x + 12) = .6}}}
{{{x + 4.8 = .6*(x + 12)}}}
{{{x + 4.8 = .6x + 7.2}}}
{{{.4x = 2.4}}}
{{{x = 6}}}
6 liters of pure antifreeze must be added