You need a 45% alcohol solution. On hand, you have a 150 mL of a 15% alcohol mixture. You also have 70% alcohol mixture. How much of the 70% mixture will you need to add to obtain the desired solution?

Answer 1

add up the amount of alcohol in each part. It must equal the alcohol in the final mixture:

.15*150 + .70x = .45(150+x)

Answer 2

368