Answer: Allison has 3/4 cups of flour left.
Step-by-step explanation:
Allison used flour twice, the first time she used 2.5 cups of flour, and the second time she used 3/4 cups of flour. Let's convert these two the the same unit.
2.5= 2 1/2 or 5/2
Let's make this have the same base so it will be easier to add 3/4 to it.
5/2=10/4
We know she used both of these amounts of flour so let's add them. 10/4+3/4=13/4
We know she used 13/4 cups of flour. Let's convert 4 cups of flour to have the denominator of 4.
4=16/4
Now, we just have to subtract how much flour she used to make the pie and cake.
16/4-13/4=3/4
Allison has 3/4 cups of flour left.