In a certain code, 'book is big' is written as 756; 'big is story' is 764 and 'story book is interesting' is 4356. Which digit represents 'interesting'?
The average revenues of 13 consecutive years of a company is Rs 78 lakhs. If the average of first 7 years is Rs 73 lakhs and that of last 7 years is Rs 85 lakhs, what is the revenue for the 7th year?