You need 760 mL of a 50% alcohol solution. On hand, you have a 95% alcohol mixture. How much of the 95% alcohol mixture and pure water will you need to obtain the desired solution?

Question

You will need.... mL of pure water

and .... mL of the 95% solution.

Answer 1

.95x + 0(760-x) = 760(.5)

x = 380/.95 = 400 mL of 95% and 360 mL of pure water