Hey!
So, the denominator tells us how many pieces there are in the pizza. (4)
4 × 1 = 4 --- That's not enough for 11 people, if each person is supposed to get 1 slice.
4 × 2 = 8 --- Still Not Enough.
4 × 3 = 12 --- This is more than enough. 11 people can each have 1 slice.
So, your answer is: Cyrus should order 3 pizzas.