Answer:2 they can only have 2 full slices of pizza
Explanation:
If they wanted to have 4 full slices there would have to be at least 24 slices
If they wanted to have 5 full slices there would have to be at least 30 slices
If they all have 2 there will only be 3 left over but not enough for each them to get another full slice
If they only all have 1 full slice there would be 9 slices left over allowing them to all have another full slice making it 2 full slices they can all eat.