The average age of 7 boys is increased by 1 year when one of tem whose age is replaced by a girl. What is the age of the girl ?
Solution
Correct Answer: Option D
Let the avg age of 7 boys be 'p' years
Let the age of the girl be 'q' years
From given data,
The age of 7 boys = 7p years
Now the new average = (p + 1) when 22 yrs is replaced by q
Now the age of all 7 will become = 7(p + 1) yrs
Hence, 7p - 22 + q = 7(p + 1) yrs
7p - 22 + q = 7p + 7
q = 22 + 7 = 29
Therefore, the age of girl = q = 29 years.
Practice More Questions on Our App!
Download our app for free and access thousands of MCQ questions with detailed solutions