What are the coordinates of the point on the directed line segment from (- 7, - 6) (-7,-6) to (3, - 10) (3,- 10)that partitions the segment into a ratio of to 3?

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?