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.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: ps: probability [#permalink]
25 Mar 2005, 10:38

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.

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.

Re: ps: probability [#permalink]
07 Apr 2005, 11:02

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.

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.

Re: ps: probability [#permalink]
07 Apr 2005, 15:09

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.

Re: ps: probability [#permalink]
07 Apr 2005, 15:17

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.

Re: ps: probability [#permalink]
07 Apr 2005, 17:59

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.

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.

Re: ps: probability [#permalink]
07 Apr 2005, 18:20

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.

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 .....

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.