A batsman makes a score of 85 runs in his 10th inning, thereby increasing his average by 2 runs. What is the average runs of the batsman after the 10th inning?

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).