Answer: Sandy.
Explanation:
Elaine has 16 tablespoons of lemonade, and uses 2 per glass.
then she can make 16/2 = 8 glasses of lemonade.
Sandy has 18 tablespoons of lemonade, and she uses 3 per glass,
then she can make 18/3 = 6 glasses of lemonade.
Then Sandy can make less glasses of lemonade than Elaine, this means that Sandy runs out of mixt first.