Algebra 1 Help?

Question

Can someone show me the steps to complete this problem? I don't understand it.
Thanks
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One antifreeze solution is 10% alcohol. Another antifreeze solution is 18% alcohol. How many liters of each antifreeze solution should be combined to create 20 liters of antifreeze solution that is 15% alcohol?

Answer 1

You have to think in terms of parts and whole. You want your whole to equal 20 liters. 1 liter of the first type has 10% meaning 1/10 is alcohol, the other type has 18% or 18/100 is alcohol.

If you use just the one type, you will have 20 parts making 10% alcohol, and if you just use the other type you will have 20 parts making 18%. The trick is finding a combination that gives you a balance of what they asked, 15%.

I need more time to figure that out, but this might help you understand to get started.

Answer 2

I think you can average it.

one is .10 per liter, one is .18.

you need to find a combination adding to 20 liters that avereages to .15.

...you add 5 to 10 to get 15, subtract 3 from 18...

so you'll need more of the 10% than the 18.

so when you do the sum of the solution percentages over 20, you should get 15.

working backwards, 15x20 is...300.

so find a combination of 10's and 18's that add up to 300, with more 10's than 18's, and try it.

I'm sorry I can't help more, but i think this is a good start!

Answer 3

sorry i absolutely hate algebra! good luck!