In a class of 35 students, the average age of the students is 17 years. If the average age of the students and their class teacher combined is 18 years, what is the age of the class teacher?

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.