Solve the problem.

-It is necessary to have a 40% antifreeze solution in the radiator of a certain car. The radiator now has 30 liters of 20% solution. How many liters of this should be drained and replaced with 100%
Antifreeze to get the desired strength?
A) 12 L
B) 7.5 L
C) 10.0 LD)15 L

Question

Solve the problem.

-It is necessary to have a 40% antifreeze solution in the radiator of a certain car. The radiator now has 30 liters of 20% solution. How many liters of this should be drained and replaced with 100%
Antifreeze to get the desired strength?
A) 12 L
B) 7.5 L
C) 10.0 LD)15 L

Quizplus · Accepted Answer

To achieve a 40% antifreeze solution, we can use the equation for concentration: (amount of antifreeze)/(total solution) = desired concentration. Initially, there are 30 liters of a 20% solution, which means there are 30*0.20 = 6 liters of antifreeze. Let x be the amount of solution to drain and replace with 100% antifreeze. After draining x liters, we have 30-x liters of the original solution, containing 20% antifreeze, and we add x liters of 100% antifreeze. The total amount of antifreeze becomes 6 - 0.20x + x, and the total solution remains 30 liters. We want the concentration to be 40%, so the equation is (6 - 0.20x + x)/30 = 0.40. Solving for x gives x = 7.5 liters.

Solve the Problem. -It Is Necessary to Have a 40% Antifreeze Solution in 40