A grocery store has 18 cartons of yogurt for sale, of which 6 are vanilla. What is the probability that a randomly selected carton of yogurt will be vanilla?

Write your answer as a fraction or whole number.

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.