A bag contains blue and green marbles in the ratio of 2 : 5. There is a total of 91 marbles in the bag. How many more blue marbles must be added into the bag so that the number of blue marbles will be the same as the number of green marbles?
The ratio of the number of banana muffins to strawberry tarts is 3 : 5. The ratio of the number of kaya cookies to the total number of banana and strawberry tarts is 5 : 1. What fraction of the tarts are strawberry tarts?