The average of six numbers is 12. Three of the numbers are 8, 9, and 16. What is the average of the other three numbers?

Question

The average of six numbers is 12. Three of the numbers are 8, 9, and 16. What is the average of the other three numbers?

Answer 1

12*6=72

8+9+16=33/3=11

x+y+z=3/3=1

11+1=12

Answer 2

Hi Rich,

The average of the other three numbers is 13.

In order for the average of six numbers to equal 12, all six numbers have to have a sum of 72 when added together because 72/6 (for six numbers) = 12.

Since three of the six numbers are 8, 9, and 16: when you add those three numbers together, you get a sum of 33.

72 - 33 = 39. Therefore, the remaining three of the six total numbers must have a sum total of 39. No matter what three other numbers you choose, their average will be 13 because 39/3 (numbers) = 13.

I hope this helps!