Brenda took her dog to the veterinarian for an exam. The doctor told Brenda her dog needed to lose weight. Her dog weighed 55 pounds during this visit. The doctor suggested that her dog 45 pounds by their next visit. What is this weight decrease represented as a percent?

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.