Quantitative Aptitude Ques 1685
Question: The average age of 45 persons is decreased by $ \frac{1}{9}yr, $ when one of them having $ 60yr $ is replaced by a new comer. Then, the age of the new comer is
Options:
A) $ 45yr $
B) $ 55yr $
C) $ 59yr $
D) $ 49yr $
Show Answer
Answer:
Correct Answer: B
Solution:
- Let the average age of 45 persons $ =x $ Then, sum of the ages $ =45x $ According to the question, $ \frac{45x+\text{(Age}ofnew\text{person)}-60}{45}=x-\frac{1}{9} $
$ \Rightarrow $ $ 45x+ $ (Age of new person) $ -,60=45( x-\frac{1}{9} ) $ Age of new person $ -60=-5 $
$ \Rightarrow $ Age of new person $ =55yr $ Alternate Method Age of new person $ =(a-nb) $ where, $ a=60, $ $ n=45, $ $ b=\frac{1}{9} $
$ \therefore $ Age of the new person $ =60-45\times \frac{1}{9}=55yr $
BETA
