A school cafeteria uses ground mince to cook lasagnas and cottage pies. They make 100 lasagnas, which use 2 pounds of ground mince each, and cottage pies, which use 3 pounds of ground mince each. If the cafeteria has used 500 pounds of ground mince in total, how many cottage pies did they make? Give me reasons, before answering the question
The cafeteria used 100 lasagnas * 2 pounds of ground mince = 200 pounds of ground mince for the lasagnas. This means they used 500 pounds of ground mince in total – 200 pounds of ground mince for the lasagnas = 300 pounds of ground mince for the cottage pies. So they must have made 300 pounds of ground mince for the cottage pies / 3 pounds of ground mince per cottage pie = 100 cottage pies. So the final answer is 100.