The average age of a group is increased by 4 years when a person whose age is 32 years is replaced by a person whose age is 56. Find the number of people in the group.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 6.
Average = Sum of observations/Number of observations
Let the number of people be n and average be x
According to the question;
⇒ n(x + 4) = nx - 32 + 56
⇒ nx + 4n = nx + 24
⇒ 4n = 24
⇒ n = 6
Thus, the total number of persons in a group is 6