Last visit was: 13 Dec 2024, 01:49 It is currently 13 Dec 2024, 01:49
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
TheNightKing
Joined: 18 Dec 2017
Last visit: 20 Mar 2024
Posts: 1,154
Own Kudos:
1,135
 []
Given Kudos: 421
Location: United States (KS)
GMAT 1: 600 Q46 V27
GMAT 1: 600 Q46 V27
Posts: 1,154
Kudos: 1,135
 []
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
User avatar
rajatchopra1994
Joined: 16 Feb 2015
Last visit: 22 Jun 2024
Posts: 1,063
Own Kudos:
1,141
 []
Given Kudos: 30
Location: United States
Posts: 1,063
Kudos: 1,141
 []
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
ganeshps77
Joined: 26 Jan 2020
Last visit: 15 Jan 2021
Posts: 9
Own Kudos:
Given Kudos: 16
Posts: 9
Kudos: 4
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
StringArgs
Joined: 08 Dec 2021
Last visit: 06 Apr 2023
Posts: 53
Own Kudos:
Given Kudos: 39
Status:Patience
Location: India
Posts: 53
Kudos: 13
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Using the concept : https://gmatclub.com/forum/statistics-made-easy-all-in-one-topic-203966.html#p1563151


The guess age of all 8 would be 40, 1 person with 55 leaves [delta change -ve(left) = 55-40] and 1 joins [delta change +ve(joins) = 39-40]

Total change per person = net delta change / remaining number
= [-(55-40) + (39-40)]/ (8-1+1)
= -16/8
= -2 (decreased by 2)

KarishmaB Please let me know if i made an error below in application of the concept because i felt a bit shaky deciding if delta should be 'what is' - 'what avg says' or the other way around to get the decrease / increase in avg.
User avatar
KarishmaB
Joined: 16 Oct 2010
Last visit: 13 Dec 2024
Posts: 15,543
Own Kudos:
70,228
 []
Given Kudos: 449
Location: Pune, India
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 15,543
Kudos: 70,228
 []
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
StringArgs
Using the concept : https://gmatclub.com/forum/statistics-made-easy-all-in-one-topic-203966.html#p1563151


The guess age of all 8 would be 40, 1 person with 55 leaves [delta change -ve(left) = 55-40] and 1 joins [delta change +ve(joins) = 39-40]

Total change per person = net delta change / remaining number
= [-(55-40) + (39-40)]/ (8-1+1)
= -16/8
= -2 (decreased by 2)

KarishmaB Please let me know if i made an error below in application of the concept because i felt a bit shaky deciding if delta should be 'what is' - 'what avg says' or the other way around to get the decrease / increase in avg.

What you have done is correct, though since a person is added and a person is reduced, you can assume that one person just shed 16 yrs (the way it would happen in case we were talking about weight reduction instead of age. Mathematically, they are equivalents).
Since 16 yrs reduced from the total with 8 people, it means it led to a reduction of 2 yrs per person.

Answer (A)
Moderator:
Math Expert
97852 posts