A cranberry juice drink mix must contain at least 15.5 percent cranberry juice by volume for proper taste. Juice Company A sells an unprocessed juice that is 12.5 percent cranberry juice and 87.5 percent other constituents for \($1.00\)/gallon. Juice Company B sells an unprocessed juice that is 20 percent cranberry juice and 80 percent other constituents for \($2.50\)/gallon.

a. What percentage of unprocessed juice should be bought from each source?

b. What is the resulting material cost per gallon of the drink?