The average of 5 numbers is found to be 9. Later on it was found that two numbers 21 and 26 were wrongly copied as 6 and 16, respectively. The correct average is:

The average of 100 numbers is 40. If one of the numbers, 30, is replaced by 70 while keeping the other numbers same, what is the new average?

The arithmetic mean of 22.5, 56, 42.5, 2x + 1, x - 2, 3x, and 36 is 30. Find the value of x (where x > 0).