There is 40% increase in an amount in 8 years at simple interest. What will be the compound interest (in rupees) of Rs 30000 after 2 years at the same rate?
In a bag, the ratio of red balls to green balls is 4:9. If 7 more red balls are added to the bag, the ratio of red balls to green balls will become 5:6. How many green balls are there in the bag?