What should be the value of x so that the average of 10,20,30,40 and x is equal to 30?

What should be the value of x so that the average of 13,15,17,15 and x is equal to 15?

What should be the value of x so that the average of 5,7,9,11 and x is equal to 7?

What should be the value of x so that the average of 11,13,15,17 and x is equal to 15?

What should be the value of x so that the average of 2,4,6,8 and x is equal to 6?

What should be the value of x so that the average of 3,5,7,9 and x is equal to 7?

What should be the value of x so that the average of 10,30,40, 50 and x is equal to 30?

What should be the value of x so that the average of 4,6,8,10 and x is equal to 6?

What should be the value of x so that the average of 2,3,4,5 and x is equal to 3?

What should be the value of x so that the average of 1,2,3,4 and x is equal to 3?