Average - General Questions

What is the average of the first 51 even numbers?

Find the average of 16, 49, 30, 77, 98, 61 and 12.

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 of 9 numbers is 37. When one more number is added, the average becomes 42. What is the new number?

The average of 15 numbers is 24. When one more number is added, the average becomes 29. What is the new number?