The average revenues of 13 consecutive years of a company is Rs 70 lakhs. If the average of first 7 years is Rs 65 lakhs and that of last 7 years is Rs 77 lakhs, find the revenue for the 7th year.
In a class when a test is conducted, mean of 25 students marks is 60 if mean of first 13 students marks is 70 and mean of last 13 students marks is 50 find the marks of the middle student when arranged in the ascending order.