FOUR balls are selected from a bag containing 15 red and 5 blue balls. What is the probability that: (a) exactly 3 are red if the balls are replaced each time?
(b) exactly 3 are red if the balls are not replaced?

21 a stick 7 inches long is broken into two pieces, so that one piece is twice as long as the other one. how long are the two pieces?

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?

What graph represents an even function