Final answer:
Francine uses 2 cups of pineapple juice for 1 cup of orange juice.
Step-by-step explanation:
To find out how many cups of pineapple juice Francine uses for 1 cup of orange juice, we need to use the given ratio of 2/3 cup of pineapple juice for every 1/3 cup of orange juice. Let's set up a proportion:
2/3 cup of pineapple juice / 1/3 cup of orange juice = x cups of pineapple juice / 1 cup of orange juice
To solve for x, we cross multiply:
2/3 * 1 = 1/3 * x
Dividing both sides by 1/3, we get:
x = (2/3) / (1/3) = 2 cups of pineapple juice
Therefore, Francine uses 2 cups of pineapple juice for 1 cup of orange juice.