In a bag the ratio of red balls to green balls is 4 : 9. If 6 more green balls were added to the bag, the ratio of red balls to green balls would become 1 : 3. How many red balls are there in the bag?
Amit's age is four times the age of Babli. Babli's age is three times the age of Priya. If the present age of Priya is 5 years, what is the present age (in years) of Amit?