The average age of 17 persons is 39 years. If the average age of the first 9 persons is 35 years, and the average age of the last 9 persons is 44 years, what is the age of the 9th person?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 48 years.
The average age of 17 persons is 39 years.
So, the Sum of the age of 7 persons = 39 × 17 = 663
The average age of the first 9 persons is 35 years.
So, the Sum of the age of the first 9 persons = 35 × 9 = 315
The average age of the last 9 persons is 44 years.
So, the Sum of the age of the first 9 persons = 44 × 9 = 396
The age of the 9th person = 396 + 315 - 663 = 48 years