Can someone help me?

Select the elements in A . A = { x : 1 < x < 50 } ξ = { x : x is a cube number } A 64 B 50 C 1 D 8 E 49 F 27 ?

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?