Alright. We are trying to find out how many pizza's they can make in every 15 mins so we can find out each hour. 45 divided by 3 is 15, and 12 divided by 3 is 4, so they can make 4 pizzas in 15 mins and multiply that by 4 is 16 pizzas in 1 hour. We are looking for 4 hours though so we just multiply 16 by 4 and we get 64.
