Question

A mechanic is working on a car that has a 10 Liter radiator that is currently filled with a mixture of water and antifreeze. thirty percent of the 10 liters is antifreeze and the rest is water. how much needs to be drained and replaced with pure antifreeze to make 10 liters of 50% antifreeze.

Answer 1

let the amount of current mixture to be removed by x

The equation which describes only the amount of antifreeze is

.3(10) - .3x + x = .5(10)

3 + .7x = 5
.7x = 2
x = 2/.7 = appr 2.86 L

He should drain 2.86 L of the current mixture and then top it up with 2.86 L of pure antifreeze