A carpenter needs 36 screws that are 1.5 inches long, 24 screws that are 2 inches long, and 12 screws that are 2.5 inches long. There are three different sized screws shown. The screws are marked two and a half inches, two inches, and one and a half inches. What is the ratio of 1.5-inch screws to 2.5-inch screws, written in three different ways? Do not reduce.