The initial ratio of sugar to flour in a dough was 2 : 7. To 9 kg of the dough John added more sugar to make the sugar to flour ratio 2 : 5. How much sugar did John later add?
The average revenues of 7 consecutive years of a company is Rs 71 lakhs. If the average of first 4 years is Rs 66 lakhs and that of last 4 years is Rs 78 lakhs. What is the revenue for the fourth year.