Answer:
She would need to order 11.5 pizzas. But of course she wouldn't order 11.5 so she'll just round up and order 12 pizzas.
Explanation:
Take 4 pieces of pizza for each person and multiply that by how many people there are in this case 23. The answer would be 92 pieces of pizza would be needed to feed all of the 23 people. So you take 92 and divide it by 4 because each person gets 4 slices and the answer you get is 11.5. If the question is a multiple choice and it gives you the option of 11.5 then that's the answer but if its a fill in then round up to 12 pizzas because if not there will not be enough pizza for everyone.
Hope this helped! :)