GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 19 Apr 2019, 09:34

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

In a certain group of people, the average weight of the males is 170

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 54371
In a certain group of people, the average weight of the males is 170  [#permalink]

Show Tags

New post 22 Aug 2017, 00:16
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

74% (01:06) correct 26% (01:41) wrong based on 67 sessions

HideShow timer Statistics

In a certain group of people, the average weight of the males is 170 pounds and of the females, 120 pounds. What is the average weight of the people in the group?

(1) The group contains twice as many females as males.
(2) The group contains 15 more females than males.

_________________
Senior PS Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3386
Location: India
GPA: 3.12
In a certain group of people, the average weight of the males is 170  [#permalink]

Show Tags

New post 22 Aug 2017, 00:25
Given data:
Average weight(Male) = 170 pounds
Average weight(Female) = 120 pounds
Let the number of females be F, and the number of males be M

1. The group contains twice as many females as males.
If the number of females is twice the number of males F:M = 2:1
Using this ratio, we can determine the average weight of the group
Average weight = \(\frac{(170*2 + 120)}{3} = \frac{460}{3}\)(Sufficient)

2. The group contains 15 more females than males.
F = M + 15
Based on the number of M, F will change and give us different averages
for every different value of M.(Insufficient)(Option A)
_________________
You've got what it takes, but it will take everything you've got
Manager
Manager
User avatar
G
Joined: 27 Dec 2016
Posts: 232
Concentration: Marketing, Social Entrepreneurship
GPA: 3.65
WE: Marketing (Education)
Reviews Badge
Re: In a certain group of people, the average weight of the males is 170  [#permalink]

Show Tags

New post 22 Aug 2017, 04:39
Bunuel wrote:
In a certain group of people, the average weight of the males is 170 pounds and of the females, 120 pounds. What is the average weight of the people in the group?

(1) The group contains twice as many females as males.
(2) The group contains 15 more females than males.


Average weight males = 170, so \(170*m = sum of the male's weight\).
Average weight females = 120, so \(120*f = sum of the females' weight\).
Average total = \(\frac{[(170*m)+(120*f)]}{(m+f)}\)

So, if we know m and m, we can calculate the average weight.

Statement 1.
- F = 2M
- Plugin into equation = \(\frac{(170m + 240m)}{3m}\). We can eliminate the m and get the absolute number.
SUFFICIENT.

Statement 2.
- F = 15+M
- Plugin into equation = \(\frac{[(170m) + 120 (15+M)]}{(m+m+15)}\). We still get "m" in our equation, no absolute value.
INSUFFICIENT.

A.
_________________
There's an app for that - Steve Jobs.
GMAT Club Bot
Re: In a certain group of people, the average weight of the males is 170   [#permalink] 22 Aug 2017, 04:39
Display posts from previous: Sort by

In a certain group of people, the average weight of the males is 170

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.