The average age of 30 students in a group is 18 years. When the teacher's age is included, the average age of the group increases by 1 year. What is the teacher's age (in years)?

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.