The average of 31 numbers is 78. The average of the first 12 numbers is 75, and the average of the last 14 numbers is 80.5. What is the average of the remaining numbers?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 78.2.
Sum of 31 numbers = 31 × 78 = 2418
Sum of first 12 numbers = 12 × 75 = 900
Sum of last 14 numbers = 14 × 80.5 = 1127
Sum of remaining 5 numbers = 2418 - (900 + 1127)
⇒ 2418 - 2027 = 391
Required average = 391/5 = 78.2