60% antifreeze and 40% water.

Question

 

The radiator in a car is filled with a solution  of 60% antifreeze and 40% 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 4.3 liters, how much coolant in liters must be drained and replaced with pure water to reduce the antifreeze concentration to 50%?

 

Answer 1

now: 4.3 liters with 60% antifreez

60% av 4.3=2.58 liter av anti

if want 50%, want 2.15 liter av anti

get rid av (2.58 -2.15)=0.43 liter

git rid=0.43/0.6=0.7166666666..

or bout 0.72 liters