In order to complete his research project, Roger needs to make a mixture of 86 mL of a 36% acid solution from a 39% acid solution and a 17% acid solution.
Find the volume of the 39% acid solution that Roger needs to use to make the mixture.

What effect would average population growth have on land usage? a. urban use of land would rise to more than 30 percent of available land. b. industrial use of land would rise to more than 30 percent of available land. c. the percentage of available land used as cropland would stay the same. d. cropland would fall to about 10 percent of available land.