Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
May 2208:30 AM PDT
-09:30 AM PDT
For many Indian MBA applicants, the default dream has long been a top US MBA. But as career goals, visa considerations, timelines, and global mobility priorities evolve, more candidates are seriously considering MBA programs in Europe.
May 2110:00 AM EDT
-11:59 PM EDT
Make the most of your break with the most realistic GMAT™ prep. Take up to $700 off select products.- Jun 10
06:00 AM PDT
-06:15 PM PDT
Register for the GMAT Club Virtual MBA Spotlight Fair – the world’s premier event for serious MBA candidates. This is your chance to hear directly from Admissions Directors at nearly every Top 30 MBA program..
26 Jan 2021, 09:00
Kudos
Bookmarks
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
65%
(hard)
Question Stats:
66% (03:03) correct
34%
(02:59)
wrong
based on 114
sessions
History
Date
Time
Result
Not Attempted Yet
The average age of three groups of people is: Group x = 83 years, Group y = 76 years, Group z = 85years, Group x and y = 79 years and Group y and z = 81years. Find the average age of all the groups.
(A) 82.5 years
(B) 81.5 years
(C) 80.5 years
(D) 79.5 years
(E) 78.5 years
(A) 82.5 years
(B) 81.5 years
(C) 80.5 years
(D) 79.5 years
(E) 78.5 years
26 Jan 2021, 10:00
Kudos
Bookmarks
Find the ratio of students and then find the average.
Follow the screenshot.
Ans B
Follow the screenshot.
Ans B
Attachments
File comment: Edited: The 2nd ratio can be found from both ways i.e 85-81=4
Delete.png [ 7.6 KiB | Viewed 4892 times ]
26 Jan 2021, 14:05
Kudos
Bookmarks
I´ve found another way. Maybe more complicated but still another option.
You know that the average of X and Y is 79, so you need to calculate:
(83x+76y)/(x+y)=79
It gives you the x:y ratio: 4:3
On the other hand, you have the average of Y and Z, meaning you calculate the same as previous:
(76y+85z)/(y+z)=81
It gives you the y:z ratio, which is 5:4
Combining both, you will realize that the ratio x:y:z is 12:15:20
In detail: 12= 4*3 (x*y), 15= 3*5 (y1*y2) and, finally, 20= 5*4 (y2*z).
The statement is asking you to find the average of x, y and, z. Now you have everything you need to do it:
(83*12+76*15+85*20)/(12+15+20)
Being x=12, y=15 and z=20, as I said before.
This results in 81,5 approx., which is answer B.
You know that the average of X and Y is 79, so you need to calculate:
(83x+76y)/(x+y)=79
It gives you the x:y ratio: 4:3
On the other hand, you have the average of Y and Z, meaning you calculate the same as previous:
(76y+85z)/(y+z)=81
It gives you the y:z ratio, which is 5:4
Combining both, you will realize that the ratio x:y:z is 12:15:20
In detail: 12= 4*3 (x*y), 15= 3*5 (y1*y2) and, finally, 20= 5*4 (y2*z).
The statement is asking you to find the average of x, y and, z. Now you have everything you need to do it:
(83*12+76*15+85*20)/(12+15+20)
Being x=12, y=15 and z=20, as I said before.
This results in 81,5 approx., which is answer B.
