60% of the students in a college class are over 25 years old. of the remain students, 50% are younger than 21. what percentage of the students are between 21 and 25?

Becca wants to mix fruit juice and soda to make a punch. she can buy fruit juice for $3 a gallon and soda for $4 a gallon. if she wants to make 28 gallons of punch at a cost of $3.25 a gallon, how many gallons of fruit juice and how many gallons of soda should she buy?