In a class of 30 students, the average score on a test is 75. If 20 students scored an average of 80, what is the average score of the remaining 10 students?

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.