Mandie is making 15 cups of fruit salad. What ratio grapes to blueberries should she use?

You've provided a tricky situation! To determine the ratio of grapes to blueberries, we need more information. Here's why:

* No Specific Amounts: The problem only tells us the total amount of fruit salad, not how much of each fruit Mandie wants to use.

To help Mandie, we need to know:

* How much of each fruit does she want? For example:

* "Mandie wants her fruit salad to be 1/3 grapes and 2/3 blueberries."

* "Mandie wants to use 5 cups of grapes."

Once we have that information, we can figure out the ratio.

Example:

Let's say Mandie wants to use 5 cups of grapes.

* Grapes: 5 cups

* Blueberries: 15 cups (total) - 5 cups (grapes) = 10 cups

* Ratio: 5 grapes : 10 blueberries (This can be simplified to 1:2)

Let me know if you can give me more details about Mandie's desired fruit proportions!