The average age of a group of 5 people is 42 years. Another group consists of 8 people whose average age is 81 years. When both groups are combined, what is the average age of all the people?

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.