The average of 27 numbers is 58. The average of the first 14 numbers is 66.6 and that of the last 14 numbers is 52.4. If the 14th number is excluded, then what is the average of the remaining numbers (correct to one decimal place)?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 56.4.
Sum of all 27 numbers = 58 × 27 = 1566
Sum of first 14 numbers = 66.6 × 14 = 932.4
Sum of last 14 numbers = 52.4 × 14 = 733.6
14th number = 932.4 + 733.6 - 1556 = 100
Sum of the remaining 26 numbers = 1566 - 100 = 1466
New average = 1466/26 ≈ 56.4