BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Average concept

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 am
Thanked: 135 times
Followed by:7 members

Average concept

by selango » Mon Jul 05, 2010 5:43 am
Each employee on a certain task force is either a manager or a director. What percent of employees on the task force are directors?
1.The average salary of managers on the task force is $5000 less than the avg salary of all the employees
2.The average salary of directors on the task force is $15000 more than the avg salary of all the employees

I solved this using algebra.Any quick method appreciated.

OA C
--Anand--
Top
Source: — Data Sufficiency |
User avatar
Community Manager
Posts: 1537
Joined: Mon Aug 10, 2009 6:10 pm
Thanked: 653 times
Followed by:252 members

by papgust » Mon Jul 05, 2010 5:58 am
Did you do a search on this question here? This question has been discussed a million times.
Download GMAT Math and CR questions with Solutions from Instructors and High-scorers:
https://www.beatthegmat.com/download-gma ... 59366.html

-----------

GO GREEN..! GO VEG..!

Daily Quote:
"Stop feeling sorry for the Butcher if you had to go Veg. The butcher can find another job but the poor animal cannot get back its life"
Top
User avatar
GMAT Instructor
Posts: 1179
Joined: Sun Apr 11, 2010 9:07 pm
Location: Milpitas, CA
Thanked: 447 times
Followed by:88 members

by Rahul@gurome » Mon Jul 05, 2010 5:58 am
Let D = no. of directors, M = no. of managers, S(M) = Avg salary of managers, S(D) = Avg salary of directors and A = avg salary of all employees.
(1) S(M) = A - 5000, which is clearly NOT SUFFICIENT.
(2) S(D) = 15000 + A, which is clearly NOT SUFFICIENT.

Combining (1) and (2), A = {S(M) × M} + {S(D) × D} / {M + D} = [(A - 5000)M + (15000 + A)D] / {M + D}
AM + AD = AM + AD - 5000M + 15000D implies 15000D = 5000M or M = 3D
So, % of employees who directors are [D/(M + D)] * 100 = (D/ 4D)*100 = 25%

The correct answer is (C).
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Top
Post new topic Post Reply
• Page 1 of 1