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?
Krish is 5 years younger than Parthiv. Eight years ago three times the age of Krish was 10 more than twice the age of Parthiv. Find Krish's present age?