Question 486402
The radiator in a car is filled with a solution of 75% antifreeze and 25% water.
 The manufacturer of the antifreeze suggests that for summer driving, optimal cooling of the engine is obtained with only 50% antifreeze.
 If the capacity of the radiator is 3.6 L, how much coolant should be drained and replaced with water to reduce the antifreeze concentration to the recommended level?
:
Let x = amt to be drained and amt of water to be added to accomplish this
:
.75(3.6-x) = .50(3.6)
2.7 - .75x = 1.8
-.75x = 1.8-2.7
-.75x = -.9
x = {{{(-.9)/(-.75)}}}
x = + 1.2 liters to be drained and replaced with 1.2 liters of water