The ratio of green balls to yellow balls in a bag is 3: 7. When 9 balls of each colour are removed, the ratio of green balls to yellow balls becomes 1: 3. How many balls were originally in the bag?
Answer Choices
A. 60
B. 90
C. 100
D. 70
E. 80
The ratio of green balls to yellow balls in a bag is 3: 7. When 9 balls of each colour are removed, the ratio of green balls to yellow balls becomes 1: 3. How many balls were originally in the bag?
Answer Choices
A. 60
B. 90
C. 100
D. 70
E. 80