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?
If you mix V litres of the first solution and W litres of the second solution, the concentration of your resulting solution will be
So just solve the two simultaneous equations in V and W for your answer.
Q: Who wrote the novels Mrs Dalloway and To the Lighthouse?