So we start with 15 pizza's, after the party 1.5 of the pizza is left which is 3 pizza's, dog ate 25% of the 3 remaining pizza's and we know that each pizza had 12 slices so 36 slices were remaining when the dog found the pizza and 25% of 36 is 9 so we take 36-9=27 then Jill eats 5 slices, so now we have 22 slices remaining so she threw away 22 slices.
