Question

Find the average of 12 numbers if the average of the first nine numbers is 21 and the average of the last three is 17.​

Answer 1

Answer:

pls forgive me as I don't know the answer as to be honest mark me brainliest

Answer 2

Answer:

20 is the average of 12number

i think it is correct answer

Step-by-step explanation:

i dont know but try like this

the average of frist 9 number =21

21=x/9

let x be total of first 9 numbers

x=21×9

x=189

the average of last 3 number= 17

17=y/3

let y be total of last 3 numbers

y= 17×3

y=51

then add both

x+y/12

=189+51/12

=240/12

=20