Math Is Fun Forum

44halfj

Member

Registered: 2008-01-27

Posts: 1

Solution Problem

How do you set this one up?

If you have an unknown amount of 30% solution and an unknown amount of 70 % solution, how much of each doyou need to make 12L of 45 % solution?

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Solution Problem

If you mix V litres of the first solution and W litres of the second solution, the concentration of your resulting solution will be

You want

and

So just solve the two simultaneous equations in V and W for your answer.