It is currently 17 Oct 2017, 21:14

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

M10 #32

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Director
Director
User avatar
Joined: 25 Oct 2008
Posts: 593

Kudos [?]: 1132 [0], given: 100

Location: Kolkata,India
M10 #32 [#permalink]

Show Tags

New post 08 Oct 2009, 02:04
The average height in a group of 4 people is 175 cm. If the average height increased when 2 more people were added to the group, which of the following cannot be the heights of the two new people?

(C) 2008 GMAT Club - m10#32

* 179 cm and 172 cm
* 181 cm and 169 cm
* 173 cm and 178 cm
* 176 cm and 176 cm
* 174 cm and 177 cm

Denote \(X\) as the sum of the heights of the two new people. From the stem it follows that \(\frac{(700 + X)}{6} \gt 175\) . This reduces to \(X \gt 350\) . Only the heights from B add up to 350 cm. All other pairs add up to more than 350 cm.
The correct answer is B.

My question is that if X>350,then should'nt the two figures add up to more than 350??How is the answer which EQUAL to 350 the answer??
_________________

http://gmatclub.com/forum/countdown-beginshas-ended-85483-40.html#p649902

Kudos [?]: 1132 [0], given: 100

1 KUDOS received
Manager
Manager
User avatar
Joined: 02 Jan 2009
Posts: 93

Kudos [?]: 93 [1], given: 6

Location: India
Schools: LBS
Re: M10 #32 [#permalink]

Show Tags

New post 08 Oct 2009, 02:11
1
This post received
KUDOS
tejal777 wrote:
The average height in a group of 4 people is 175 cm. If the average height increased when 2 more people were added to the group, which of the following cannot be the heights of the two new people?

(C) 2008 GMAT Club - m10#32

* 179 cm and 172 cm
* 181 cm and 169 cm
* 173 cm and 178 cm
* 176 cm and 176 cm
* 174 cm and 177 cm

Denote \(X\) as the sum of the heights of the two new people. From the stem it follows that \(\frac{(700 + X)}{6} \gt 175\) . This reduces to \(X \gt 350\) . Only the heights from B add up to 350 cm. All other pairs add up to more than 350 cm.
The correct answer is B.

My question is that if X>350,then should'nt the two figures add up to more than 350??How is the answer which EQUAL to 350 the answer??


The average height of the people already is 175.

So if we add a group of people with average height more than 175 the total average will increase (as desired in the question)

But if you add a group of people with average height as 175, the total average will remain at 175 and not increase. Thus this group can not be the one added.

Hope it is clear now :)
_________________

The Legion dies, it does not surrender.

Kudos [?]: 93 [1], given: 6

Re: M10 #32   [#permalink] 08 Oct 2009, 02:11
Display posts from previous: Sort by

M10 #32

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

Moderator: Bunuel



GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.