Part A) To find what percent of the paint is red, you divide the part (5) by the whole (15 + 5 = 20)
Answer: 5/20 = 25%
Part B) To simplify the 15:5 ratio of yellow paint to red paint, you determine what number both 5 and 15 is divisible by. Both 5 and 15 are divisible by 5.
15/5 = 3 and 5/5 = 1 Therefore, the simplified ratio is 3/1 or 3:1 (read as 3 to 1)