Mrs. Amaro has 80 roses in her garden. Three-fourths of her roses are red, one-fourth of the remaining are yellow, and the rest are white. How many of Mrs. Amaro's roses are either red or white? Let's answer step by step:
Mrs. Amaro has 80 x 3 / 4 = 60 red roses. So, 80 - 60 = 20 roses are not red. Then, 20 x 1 / 4 = 5 of those 20 non - red roses are yellow. Hence, 20 - 5 = 15 roses are white. Therefore, 60 + 15 = 75 roses are either red or white. The answer: 75.