What will be the volume of water needed to make a 15% concentrated hundred mL ethanol solution?

>

A solution contains 40 mL of ethyl alcohol mixed with 100 mL of water. What is the concentration of the solution in terms of volume by volumepercentage?

>

A solution contains 30 mL of ethyl alcohol mixed with 100 mL of water. The concentration of the solution in terms of volume by volume percentage is %