Average - General Questions

The average weight of 11 persons increases by 1.5 kg when a new person replaces one of them weighing 52 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 33 odd numbers?

The average of 20 numbers is 29. When one more number is added, the average becomes 31. What is the new number?

What is the average of the first 51 even numbers?