Fifty balls numbered 1 through 50 are mixed up in a barrel. how many balls must you draw from the barrel (without looking) to be sure that you have two even-numbered balls?

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?