First work out how much punch is needed.
9 friends+Sally=10 people.
So 2 glasses each makes 20 glasses in all.
I glass holds 300mL.
Total amount of punch=20×300=6000mL=6L.
The recipe is for 1L. She needs 6L so every ingredient is multiplied by 6:
(1) 6 limes, 6 lemons, 900mL of pineapple juice, 3L of lemonade, 1.8L orange juice.
P juice: $1.25 (she would need to buy one carton, from which she would use 900mL)
Lemonade: $3.70 (two 2L-bottles needed for 3L of lemonade. 2 bottles would provide 4L)
O juice: $1.90 (2 1L-cartons needed for 1.8L)
TOTAL COST: $14.95