We have to find how many purple rectangles does Olivia need for 3 scarves. We know that each scarf will have 5 rectangles and 2/5 of the rectangles will be purple: 2/5 * 5 = 2. It means that each scarf will have 2 purple rectangles. And for 3 scarves : 3 * 2 = 6. Answer: She needs 6 purple rectangles.