set problem

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 45
Joined: Mon May 26, 2008 4:12 pm

set problem

by ch0719 » Mon Oct 27, 2008 5:22 pm
x,3,1,12,8

If x is an integer, is the median of the 5 numbers shown greater than the average (arithmetic mean) of the 5 numbers?

1. x>6
2. x is greater than the median of the 5 numbers


oa tba

Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pm
Thanked: 331 times
Followed by:11 members

by cramya » Mon Oct 27, 2008 5:30 pm
I get E)

OA,please?

Hi Ch,
Friendly request: If you could post the OA wiht the spoiler function going forward it would be much appreciated!

User avatar
Legendary Member
Posts: 2134
Joined: Mon Oct 20, 2008 11:26 pm
Thanked: 237 times
Followed by:25 members
GMAT Score:730

by logitech » Mon Oct 27, 2008 6:15 pm
cramya wrote:I get E)

OA,please?

Hi Ch,
Friendly request: If you could post the OA wiht the spoiler function going forward it would be much appreciated!
I agree both with your spoiler request and E choice.

1) Insuf X can be 1000000000000 and the mean can;t be greater than the AV

2) Insuf - it only tells us that x > 12 and with the same logic in (1) it can be 10000000000000 and mean can't be greater than AV
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"

Senior | Next Rank: 100 Posts
Posts: 45
Joined: Mon May 26, 2008 4:12 pm

by ch0719 » Mon Oct 27, 2008 7:35 pm
Yes E is correct

Sry I didn't know how to do the spoiler thing at first, now I do :)

Newbie | Next Rank: 10 Posts
Posts: 7
Joined: Sun Oct 19, 2008 12:09 am
Location: Faisalabad, Pakistan

by tkhalid » Mon Oct 27, 2008 9:57 pm
Sir, what is "AV"?

User avatar
Legendary Member
Posts: 2134
Joined: Mon Oct 20, 2008 11:26 pm
Thanked: 237 times
Followed by:25 members
GMAT Score:730

by logitech » Mon Oct 27, 2008 11:49 pm
tkhalid wrote:Sir, what is "AV"?
average (arithmetic mean)
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"

User avatar
Senior | Next Rank: 100 Posts
Posts: 48
Joined: Sun Sep 28, 2008 3:59 pm
Location: Miami, FL
Thanked: 2 times
Followed by:1 members
GMAT Score:760

by praneeth » Thu Nov 06, 2008 7:07 pm
logitech wrote:
cramya wrote:I get E)

OA,please?

Hi Ch,
Friendly request: If you could post the OA wiht the spoiler function going forward it would be much appreciated!
I agree both with your spoiler request and E choice.

1) Insuf X can be 1000000000000 and the mean can;t be greater than the AV

2) Insuf - it only tells us that x > 12 and with the same logic in (1) it can be 10000000000000 and mean can't be greater than AV
Agree with the answer but the reasoning has to rule out a definite "No" to the question, as a definite "No" would make the statements sufficient as well.

To rule out a definite No:

From statement two, we basically know that if X is higher than the median, which implies that the median has to be 8. Since the sum of the four numbers given is 24, if X is 9 then the arithmetic average is 33/5 = less than 8 (the median), however if X is instead something large like 21, the arithmetic average is 45/5 = 9 (greater than 8 - the median). Therefore a definite "No" is not possible in this case.

Therefore answer is E.

Master | Next Rank: 500 Posts
Posts: 207
Joined: Sun Mar 11, 2007 6:16 pm
Location: Mumbai
Thanked: 11 times

by jimmiejaz » Fri Nov 07, 2008 1:58 am
[quote="praneeth]Agree with the answer but the reasoning has to rule out a definite "No" to the question, as a definite "No" would make the statements sufficient as well.

To rule out a definite No:

From statement two, we basically know that if X is higher than the median, which implies that the median has to be 8. Since the sum of the four numbers given is 24, if X is 9 then the arithmetic average is 33/5 = less than 8 (the median), however if X is instead something large like 21, the arithmetic average is 45/5 = 9 (greater than 8 - the median). Therefore a definite "No" is not possible in this case.

Therefore answer is E.[/quote]

hi,

can u pls explain how the median is 8?

Master | Next Rank: 500 Posts
Posts: 207
Joined: Sun Mar 11, 2007 6:16 pm
Location: Mumbai
Thanked: 11 times

by jimmiejaz » Fri Nov 07, 2008 2:03 am
logitech wrote:

2) Insuf - it only tells us that x > 12 and with the same logic in (1) it can be 10000000000000 and mean can't be greater than AV
Logitech,

Shouldnt stmt 2 give us x>8 instead of x>12? Am i missing something here?

User avatar
Senior | Next Rank: 100 Posts
Posts: 48
Joined: Sun Sep 28, 2008 3:59 pm
Location: Miami, FL
Thanked: 2 times
Followed by:1 members
GMAT Score:760

by praneeth » Fri Nov 07, 2008 5:04 am
jimmiejaz wrote:[quote="praneeth]Agree with the answer but the reasoning has to rule out a definite "No" to the question, as a definite "No" would make the statements sufficient as well.

To rule out a definite No:

From statement two, we basically know that if X is higher than the median, which implies that the median has to be 8. Since the sum of the four numbers given is 24, if X is 9 then the arithmetic average is 33/5 = less than 8 (the median), however if X is instead something large like 21, the arithmetic average is 45/5 = 9 (greater than 8 - the median). Therefore a definite "No" is not possible in this case.

Therefore answer is E.
hi,

can u pls explain how the median is 8?[/quote]

If X is smaller than 8 and larger than the median the numbers would look something like:

1, 3, X, 8 12

since there are only two numbers smaller than X, and two numbers greater than X no other number can be the median, i.e. X has to be the median which doesn't satisfy our assumption that X is greater than the median.

There are only two numbers smaller than 8 in the data set, therefore for X to be greater than the median X has to be greater than 8.

Master | Next Rank: 500 Posts
Posts: 207
Joined: Sun Mar 11, 2007 6:16 pm
Location: Mumbai
Thanked: 11 times

by jimmiejaz » Fri Nov 07, 2008 5:22 am
hi praneeth,

thanks for the explanation. Actually, i got confused. In the post above yours, i had deduced the same that x>8 for x to be greater than the median. I asked x>8 and you wrote median = 8. both are different interpretations for the same thing.
cheers!!!!!