NEW HERE? LEARN MORE
closeclose
Last visit was: 24 Apr 2024, 14:27 It is currently 24 Apr 2024, 14:27
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

M22-15

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92902
Own Kudos [?]: 618804 [8]
Given Kudos: 81588
Send PM
CAT Tests Forum Quiz Mode
M22-15 [#permalink] New post   16 Sep 2014, 01:16
1
Kudos
7
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

35% (medium)

Question Stats:

69% (01:36) correct 31% (01:49) wrong based on 142 sessions
Hide Show timer Statistics
\(\{2, 3, 5, 7\}\)

Upon adding \(x\) as a fifth term to the list above, the median of the list increases by 25%. Which of the following cannot be the value of \(x\)?


A. 4.8
B. 5.0
C. \(\sqrt{29}\)
D. 7.7
E. \(\frac{49}{4}\)
ShowHide Answer
Official Answer
A
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92902
Own Kudos [?]: 618804 [4]
Given Kudos: 81588
Send PM
CAT Tests Forum Quiz Mode
Re M22-15 [#permalink] New post   16 Sep 2014, 01:16
1
Kudos
3
Bookmarks
Expert Reply
Official Solution:


\(\{2, 3, 5, 7\}\)

Upon adding \(x\) as a fifth term to the list above, the median of the list increases by 25%. Which of the following cannot be the value of \(x\)?


A. 4.8
B. 5.0
C. \(\sqrt{29}\)
D. 7.7
E. \(\frac{49}{4}\)


The original list was \(\{2, 3, 5, 7\}\). Its median was \(\frac{3 + 5}{2} = 4\). With the addition of a term, the new median becomes \(4*1.25 = 5\). Since the median of a list with an odd number of terms (5 in this instance) is the middle term when sorted in ascending or descending order, the new list can be:

\(\{2, \ 3, \ 5, \ x, \ 7\}\) or \(\{2, \ 3, \ 5, \ 7, \ x\}\)

Thus, \(x\), the number added, cannot be less than 5. If \(x\) were less than 5, the median (the middle term) would no longer be 5.

The only option that is less than 5 is A (4.8).


Answer: A
avatar
B
sevenplusplus
Manager
Manager
Joined: 23 Jun 2016
Posts: 63
Own Kudos [?]: 32 [0]
Given Kudos: 44
Send PM
Re: M22-15 [#permalink] New post   15 Nov 2017, 22:54
since the new median is 5, all options except B are wrong....????

in other words, if the question mentioned that the median grew by atleast 35%, A would be the answer.
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92902
Own Kudos [?]: 618804 [3]
Given Kudos: 81588
Send PM
CAT Tests Forum Quiz Mode
Re: M22-15 [#permalink] New post   15 Nov 2017, 23:18
3
Kudos
Expert Reply
sevenplusplus wrote:
If after a number was added to a set consisting of all distinct one-digit prime integers, the median of the set grew by 25%, which of the following cannot be the value of the number added?

A. 4.8
B. 5.0
C. \(\sqrt{29}\)
D. 7.7
E. \(\frac{49}{4}\)


The original set was \(\{2, 3, 5, 7\}\). Its median was \(\frac{3 + 5}{2} = 4\). The median of the new set \(= 4*1.25 = 5\). Thus, the number added cannot be less than 5.


Answer: A

since the new median is 5, all options except B are wrong....????

in other words, if the question mentioned that the median grew by atleast 35%, A would be the answer.


You are wrong.

The original set = {2, 3, 5, 7}.
The original median = 4.


B. New number = 5;
New set = {2, 3, 5, 5, 7}.
New median = 5.

C. New number = \(\sqrt{29}\);
New set = 2, 3, 5, \(\sqrt{29}\), 7}.
New median = 5.

D. New number = 7.7;
New set = {2, 3, 5, 7, 7.7}.
New median = 5.

E. New number = \(\frac{49}{4}\);
New set = {2, 3, 5, 7, 49/4}.
New median = 5.
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92902
Own Kudos [?]: 618804 [0]
Given Kudos: 81588
Send PM
CAT Tests Forum Quiz Mode
Re: M22-15 [#permalink] New post   08 Sep 2023, 10:10
Expert Reply
I have edited the question and the solution by adding more details to enhance its clarity. I hope it is now easier to understand.
GMAT Club Bot
gmatclubot
Re: M22-15 [#permalink]
08 Sep 2023, 10:10
Moderator:
Bunuel
Math Expert
92902 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions