Find average of 12 numbers if the average of the first 8 numbers is 21 and the average of the last four numbers is 18.

The average of 21 numbers is 12. The average of the first 11 numbers is 9 and the average of the last 11 numbers is 15. What is the value of the middle number ?

lf the average of 35 numbers is 22, the average of the first 17 numbers is 19. and the average of the last 17 numbers is 20, then the 18^th number is:

The average of 40 numbers is 36. The average of the first 25 numbers is 31 and the average of last 16 numbers is 43. Find the 25^(th) number

The average of 9 numbers is 18. If the average of first five numbers is 19 and the average of last 5 numbers is 17, find the 5th number.

The average of five numbers is 612. If the average of the first two numbers is 418 and the average of the last two numbers is 521. find the third number.

The average of five numbers is 58. The average of the first two numbers is 48.5 and the average of last two numbers is 53.5 .What is the third number?