The average of 12 numbers is 15 and the average of the first two numbers is 14. What is the average of the remaining numbers?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 15.2
The sum of a set of numbers = their average × how many there are, so the sum of the other ten numbers is the total less the sum of the first two.
Sum of all 12 numbers \(=12\times15=180\)
Sum of the first two \(=2\times14=28\)
Sum of the remaining 10 \(=180-28=152\)
Their average \(\displaystyle=\frac{152}{10}=15.2\)