The mean of 10 observations is 25. On checking, it was found that two observations were wrongly copied as 6 and 9. If these wrong observations are replaced by the correct values 4 and 5, then the correct mean will be:

What is the average number of students in B.Tech (220), M.Tech (140), and B.A (4344) courses together?

A class has two sections A and B, which have 36 and 44 students respectively. If the average weight of section A is 40 kg and that of section B is 35 kg, find the average weight of the whole class.