The average age of a group of 5 members is 20 years...

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The average age of a group of 5 members is 20 years. Two years later, a new member joins the group. The average age of the group becomes 22 years. What is the age of the new member?

A. 20 years
B. 21 years
C. 22 years
D. 23 years
E. 24 years

The OA is C.

Please, can any expert explain this PS question for me? I tried to solve it but i'm not sure because the answer is so obvious! I need your help. Thanks.

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by [email protected] » Wed Jan 03, 2018 10:53 am
Hi swerve,

We're told that the average age of a group of 5 members is 20 years. TWO years LATER, a new member joins the group and the average age of the group becomes 22 years. We're asked for the age of the new member.

This question doesn't require any heavy calculations IF you recognize the 'twist' involved. With the original group of 5 members who have an average age of 20, when you move that group 2 years into the future, the average age would be 22 (since they would all be 2 years older). So, by including a 6th person to that group and having the average STAY 22, the age of the 6th person must be 22.

Final Answer: C

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by Scott@TargetTestPrep » Mon Sep 02, 2019 6:09 pm
swerve wrote:The average age of a group of 5 members is 20 years. Two years later, a new member joins the group. The average age of the group becomes 22 years. What is the age of the new member?

A. 20 years
B. 21 years
C. 22 years
D. 23 years
E. 24 years

The OA is C.

Please, can any expert explain this PS question for me? I tried to solve it but i'm not sure because the answer is so obvious! I need your help. Thanks.
If the new member has not joined the group, the average age of the group is 22 years (since 2 years earlier their average age was 20). Therefore, in order for the new member to keep the average age of the group as 22, he or she is also 22 years old.

Answer: C

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