Find the Average Age of Remaining 4 New Students :

The average age of 30 students of a class is 14 years 4 months. After admission of 5 new students in the class the average becomes 13 years 9 months. The youngest one of the five new students is 9 years 11 months old. The average age of remaining 4 new students is

1. 10 years 4 months
2. 12 years 4 months
3. 11 years 2 months
4. 13 years 6 months
Anurag Mishra Professor Asked on 26th October 2015 in

Answer is (1): 10 years 4 months

Explanation:-
The average of 30 students of a class = 14 years and 4 moths
Then, the total age of 30 students of a class = 30 x 14 and 30 x 4
= 420 years 120 months
= 420 + 10
= 430 years
After admission of 5 new students in the class average becomes 13 years 9 months,
13 years 9 months
Then, the total of all students = 35 x 13 years 9 x 35
= 455 years  315 months
= 455 + 26 years and 3 months
= 481 years and 3 months
Therefore,  the total age of five new students = 481 years 3 months- 430 years
= 51 years 3 months
The age of the youngest one of the five new students = 9 years 11 months
Then, the age of remaining four students = 51 years 3 month – 9 years 11 months
= 41 years 8 months

So, the average of 4 new students = 41 years 4 months/4
10 years 4 months

Hence, the answer is (1) 10 years 4 months

Monis Rasool Professor Answered on 28th October 2015.