Three numbers are such that when the average of any two of them is added to the third, the results obtained are 200, 190, and 170, respectively. What is the average of the original three numbers?

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).