Question

The average of 9 numbers is 3. If the average of the first 8 of these numbers is 2, the 9 th number is:

• A. 11
• B. 12
• C. 14
• D. 15

Answer 1

Answer:

A. 11

Average of 9 numbers = 3
So, sum of 9 numbers:
$9 \times 3 = 27$

Average of first 8 numbers = 2
So, sum of first 8 numbers:
$8 \times 2 = 16$

9th number:

27 - 16 = 11

Final Answer: 11