# Homework Help: Word problem

1. Jul 1, 2013

### theoristo

The radiator of a car can contain 10 gal of liquid. If it is half full with a
mixture having 60% antifreeze and 40% water, how much more water
must be added so that the resulting mixture has only
a) 40% antifreeze? b) 10% antifreeze?
Will it fit in the radiator?

2. Jul 1, 2013

### Ray Vickson

Show your work. At the very least, define some variables that must be found in order to solve your problem. Then try to write some equations that those variables must satisfy. You really do need to be able to do this on your own if you want to pass the course. We can help, but we can't do the problem for you.

3. Jul 1, 2013

### theoristo

Sorry I didn't want the solution I just wanted to share it.

4. Jul 2, 2013

### youngreezy

3/5 = % antifreeze
2/5 = % water
half-full = 5 gallons of mixture

If 5 gallons is in the radiator, and 3/5 of it is antifreeze, then there must be 3 gallons of antifreeze in the radiator. Similarly, the other 2/5 must be water.

a.) remember that (amount of antifreeze)/(total) x 100 = % antifreeze
Since you know the desired amount of antifreeze, we must add a certain amount of water to the total mixture in order to reduce the percentage of antifreeze. (3)/(5 + x gal of water) = (2/5)

b.) same as part a.) but more water must be added