Mixture Algebra x1

Question

You need a 65% alcohol solution. On hand, you have a 130 mL of a 15% alcohol mixture. You also have 75% alcohol mixture. How much of the 75% mixture will you need to add to obtain the desired solution?

Answer 1

650 mL of 75% solution added to 130 mL of 15% will yield 780 mL of 65% solution

130(15) +X(75) = (X+130)65

10X = 6500

X = 650