Question

find the average of 12 number the average if 8 number is 21 and average of last 8 number is 21 and last 4 is 18 ​

Answer 1

Step-by-step explanation:

Average of first 8 number = 21

Average of first 8 number = 21Average of last 4 number = 18

Average of first 8 number = 21Average of last 4 number = 18If average of all 12 numbers is 18, then we have 8 x 3 = 24 extra from first eight numbers.

Average of first 8 number = 21Average of last 4 number = 18If average of all 12 numbers is 18, then we have 8 x 3 = 24 extra from first eight numbers.This extra is distributed over all 12 numbers increasing their average by 24/12 = 2.

Average of first 8 number = 21Average of last 4 number = 18If average of all 12 numbers is 18, then we have 8 x 3 = 24 extra from first eight numbers.This extra is distributed over all 12 numbers increasing their average by 24/12 = 2.=> Final average = 18 + 2 = 20

Answer 2

Answer:

Average of first 8 number = 21Average of last 4 number = 18If average of all 12 numbers is 18, then we have 8 x 3 = 24 extra from first eight number.

final ans were is 20