Average - General Questions

The average marks of a class of 29 students is 48 and that of another class of 22 students is 52. What is the average of all the students together?

The average weight of 8 persons increases by 3 kg when a new person replaces one of them weighing 55 kg. What is the weight of the new person?

The average weight of 8 persons increases by 2.5 kg when a new person replaces one of them weighing 73 kg. What is the weight of the new person?

What is the average of the first 70 natural numbers?

The average of 13 numbers is 34. When one more number is added, the average becomes 39. What is the new number?