Question 222797
A car's radiator contains 12L of antifreeze at 25% concentration. How many liters must be drained and then replaced by pure antifreeze to bring the concentration to 50%?
.
Let x = amount removed and replaced w/pure antifreeze
then
x + .25(12-x) = .50(12)
x + 4 - .25x = 6
x - .25x = 2
.75x = 2
x = 2/.75
x = 2.67 liters