Please help answer with steps thanks so much.

Question

The radiator in a car is filled with a solution of 70 per cent antifreeze and 30 per cent water. The manufacturer of the antifreeze suggests that for summer driving, optimal cooling of the engine is obtained with only 50 per cent antifreeze. If the capacity of the radiator is 3.4 liters, how much coolant (in liters) must be drained and replaced with pure water to reduce the antifreeze concentration to 50 per cent?

Answer 1

Michael, right now the radiator has .7(3.4) = 2.38 liters of antifreeze and 1.02 liters of water.

 

We need 1.7 liters of each, so we need to drain 0.68 of antifreeze and add 0.68 of water, which we can't just do, of course, so we'll have to drain 1.36 liters to get us to 1.7 liters of antifreeze and 0.34 liters of water. Putting 1.36 liters of water gets us to our 50/50 mix.

 

Hope this helps!