When specifying a quantity for ingredients like cups of flour in a recipe, the number must be non-negative and typically a whole number or a positive rational number.
From the given options, the following numbers can be used to specify how many cups of flour should be used:
- 2
- 3
- 4
- 4 (duplicate, but valid)
- 7
The other numbers cannot be used:
- −3 is negative, which is not valid for the quantity of flour.
- square root of 3 is a positive number, but it is not a whole number, so it would be less common to use it in a recipe.
In conclusion, the valid whole or positive number options for the amount of flour are 2, 3, 4, and 7.