Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 28 May 2017, 14:34

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# ps: probability

Author Message
Senior Manager
Joined: 02 Feb 2004
Posts: 345
Followers: 1

Kudos [?]: 66 [0], given: 0

### Show Tags

25 Mar 2005, 06:39
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

hmm........
Attachments

0017.jpg [ 14.1 KiB | Viewed 893 times ]

Senior Manager
Joined: 15 Mar 2005
Posts: 418
Location: Phoenix
Followers: 2

Kudos [?]: 27 [0], given: 0

### Show Tags

25 Mar 2005, 11:38
mirhaque wrote:
hmm........

The area of the square would be > 1 if perimeter > 4.
Thus the "allowed" length of the wire to be cut is upto 1 m from either end.
Thus 2 m out of 5 m is the allowed "cuttable" length.

0..........1............2............3.............4..............5
---------------------------------------------------------
|cuttable|..........................................|.cuttable.|

Thus probability = 0.4.
_________________

Who says elephants can't dance?

Manager
Joined: 17 Dec 2004
Posts: 71
Followers: 2

Kudos [?]: 13 [0], given: 0

### Show Tags

27 Mar 2005, 23:19
I'm very impressed with your diagram, kapslock!

I agree - for a square of at least area 1, the perimeter must be at least 4. If you have a wire that is 5 meters long, you can afford to cut off up to 1 meter from either end. The likelihood that you'll do this is 2/5 or 0.4.
VP
Joined: 30 Sep 2004
Posts: 1482
Location: Germany
Followers: 6

Kudos [?]: 349 [0], given: 0

### Show Tags

07 Apr 2005, 12:02
kapslock wrote:
mirhaque wrote:
hmm........

The area of the square would be > 1 if perimeter > 4.
Thus the "allowed" length of the wire to be cut is upto 1 m from either end.
Thus 2 m out of 5 m is the allowed "cuttable" length.

0..........1............2............3.............4..............5
---------------------------------------------------------
|cuttable|..........................................|.cuttable.|

Thus probability = 0.4.

but when i cut 1 meter, the remaining lenght is 4 meters and this would be equal to an area of 4, wouldnt it ? the q asks for a p greater than 1...
_________________

If your mind can conceive it and your heart can believe it, have faith that you can achieve it.

Senior Manager
Joined: 15 Mar 2005
Posts: 418
Location: Phoenix
Followers: 2

Kudos [?]: 27 [0], given: 0

### Show Tags

07 Apr 2005, 16:09
christoph wrote:
kapslock wrote:
mirhaque wrote:
hmm........

The area of the square would be > 1 if perimeter > 4.
Thus the "allowed" length of the wire to be cut is upto 1 m from either end.
Thus 2 m out of 5 m is the allowed "cuttable" length.

0..........1............2............3.............4..............5
---------------------------------------------------------
|cuttable|..........................................|.cuttable.|

Thus probability = 0.4.

but when i cut 1 meter, the remaining lenght is 4 meters and this would be equal to an area of 4, wouldnt it ? the q asks for a p greater than 1...

Christoph, let me try to clarify.

Remaining length 4 m => perimeter of the square = 4 m
This is a square of side 1m, and area = 1.
This is what they've asked for the question. Right?

And yes, the question asked for area greater than 1, not p. The p (probability) is what we have to calculate.

Hope that helps. Let me know if you'd need some clarification.
_________________

Who says elephants can't dance?

Director
Joined: 18 Feb 2005
Posts: 670
Followers: 1

Kudos [?]: 6 [0], given: 0

### Show Tags

07 Apr 2005, 16:17
kapslock wrote:
mirhaque wrote:
hmm........

The area of the square would be > 1 if perimeter > 4.
Thus the "allowed" length of the wire to be cut is upto 1 m from either end.
Thus 2 m out of 5 m is the allowed "cuttable" length.

0..........1............2............3.............4..............5
---------------------------------------------------------
|cuttable|..........................................|.cuttable.|

Thus probability = 0.4.

If you are cutting exactly 1 m still your not getting area >1 right?
Senior Manager
Joined: 15 Mar 2005
Posts: 418
Location: Phoenix
Followers: 2

Kudos [?]: 27 [0], given: 0

### Show Tags

07 Apr 2005, 18:59
gmat2me2 wrote:
kapslock wrote:
mirhaque wrote:
hmm........

The area of the square would be > 1 if perimeter > 4.
Thus the "allowed" length of the wire to be cut is upto 1 m from either end.
Thus 2 m out of 5 m is the allowed "cuttable" length.

0..........1............2............3.............4..............5
---------------------------------------------------------
|cuttable|..........................................|.cuttable.|

Thus probability = 0.4.

If you are cutting exactly 1 m still your not getting area >1 right?

You're right, but this is a case of limits.

Lets put it this way.

If cuttable length (on either side) = 0.5 m, area = 1.265625
If cuttable length (on either side) = 0.75 m, area = 1.1289
If cuttable length (on either side) = 0.875 m, area = 1.06347
If cuttable length (on either side) = 0.95 m, area = 1.02515
If cuttable length (on either side) = 0.99 m, area = 1.00500625
If cuttable length (on either side) = 0.999 m, area = 1.0005

So you see, as Limit (cuttable length -> 1), area -> 1.

And as Limit (cuttable length -> 1), p -> 0.4.

Hope that helps.
_________________

Who says elephants can't dance?

Director
Joined: 18 Feb 2005
Posts: 670
Followers: 1

Kudos [?]: 6 [0], given: 0

### Show Tags

07 Apr 2005, 19:20
kapslock wrote:
gmat2me2 wrote:
kapslock wrote:
mirhaque wrote:
hmm........

The area of the square would be > 1 if perimeter > 4.
Thus the "allowed" length of the wire to be cut is upto 1 m from either end.
Thus 2 m out of 5 m is the allowed "cuttable" length.

0..........1............2............3.............4..............5
---------------------------------------------------------
|cuttable|..........................................|.cuttable.|

Thus probability = 0.4.

If you are cutting exactly 1 m still your not getting area >1 right?

You're right, but this is a case of limits.

Lets put it this way.

If cuttable length (on either side) = 0.5 m, area = 1.265625
If cuttable length (on either side) = 0.75 m, area = 1.1289
If cuttable length (on either side) = 0.875 m, area = 1.06347
If cuttable length (on either side) = 0.95 m, area = 1.02515
If cuttable length (on either side) = 0.99 m, area = 1.00500625
If cuttable length (on either side) = 0.999 m, area = 1.0005

So you see, as Limit (cuttable length -> 1), area -> 1.

And as Limit (cuttable length -> 1), p -> 0.4.

Hope that helps.

Agreed.....It cannot be a solid value ....It has to be close to some value as you have mentioned .....
VP
Joined: 30 Sep 2004
Posts: 1482
Location: Germany
Followers: 6

Kudos [?]: 349 [0], given: 0

### Show Tags

08 Apr 2005, 00:14
i understand, kapslock, but i think it is not clearly stated in the question.
_________________

If your mind can conceive it and your heart can believe it, have faith that you can achieve it.

Senior Manager
Joined: 19 Feb 2005
Posts: 486
Location: Milan Italy
Followers: 1

Kudos [?]: 23 [0], given: 0

### Show Tags

08 Apr 2005, 02:13
christoph wrote:
i understand, kapslock, but i think it is not clearly stated in the question.

kapslock is right. To clarify further, I would add that in this case P(x<4)=P(x<=4) because in statistics, when we talk about a continuous probability function, P(x=4 or whatever)=0.This is always valid for continuous functions, so it was not necessary for the question to make it explicit.
08 Apr 2005, 02:13
Display posts from previous: Sort by