Answer:
2.03 liters of 30% antifreeze should be drained and replaced with 100% antifreeze to get the desired strength.
Explanation:
Since a car radiator needs a 40% antifreeze solution, and the radiator now holds 14 liters of a 30% solution, to determine how many liters of this should be drained and replaced with 100% antifreeze to get the desired strength the following calculation must be performed:
100 x 0.3 + 0 x 1 = 30
90 x 0.3 + 10 x 1 = 37
85 x 0.3 + 15 x 1 = 40.5
86 x 0.3 + 14 x 1 = 39.8
85.8 x 0.3 + 14.2 x 1 = 39.94
85.7 x 0.3 + 14.3 x 1 = 40.01
85.71 x 0.3 + 14.29 x 1 = 40
100 = 14
14.29 = X
14.29 x 14/100 = X
200.06 / 100 = X
2.03 = X
Therefore, 2.03 liters of 30% antifreeze should be drained and replaced with 100% antifreeze to get the desired strength.