Name: Abdu
Who is asking: Student
Level: Secondary
Question:
80,80,84,85,88,92,97,98
The average of the 8 numbers listed above is 88. Of the following which pair of numbers could be removed from the list without changing the average.
B. 80 and 98
C. 84 and 92
D. 84 and 97
E. 85 and 92
Hi Abdu,
Ask an easier question first. From the list you have which one number could be removed without changing the average? Why is it that you can remove that one without changing the average?
When you find the average of all 8 numbers you add them and then divide by 8. The answer is 88 so the sum of all 8 numbers must be 8 
88. When you remove one number and still have an average of 88 then the sum of the 7 numbers must be 7 88.
Which pair of numbers could be removed from the list without changing the average?
Andrei and Penny