Question

how many liters of a 15% alcohol solution must be mixed with 30 liters of a 40% alcohol solution to obtain a 30% solution

Answer 1

Answer: 20 liters

Explanation:

Let the number of liters of 15% alcohol solution be
`x`.

`0.15x+30(0.4)=0.3(x+30)\\\\0.15x+12=0.3x+9\\\\12=0.15x+9\\\\0.15x=3\\\\x=20`