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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 350,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

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: Is the area of the triangle ABC more than 12 sq. units? [#permalink]
05 May 2013, 01:12

1

This post received KUDOS

vinaymimani wrote:

Is the area of the triangle ABC more than 12 sq. units?

I. The GCD of the sides AB and AC is 2.

II. The LCM of the sides AB and AC is 12.

OA and OE after some brainstorming.

A is not sufficient as we will have a Number of AB, AC lengths that can have a GCD of 2. For Eg: 4,6 8,10. For Different AB AC values, the range of the third side will vary.

B is also not sufficient as we will have a number of AB AC lengths that can have LCM 12. For Eg: 4,3 6,12 1,12

If we take A and B together we will have : AB * AC=24. Now if AB and AC are Base and height of the triangle, then we will have the Area as 12. which is not more than 12(as per question)

if we do not have AB and AC Base and height then, AB and AC should be 4 and 6 respectively. That means AC should lie between 2 and 10. If we take AC=8, then using sqrt [s(s-a)(s-b)(s-c)] formula we will have area less than 12. If we have AC =3, then we will have the area nearly 5. IE, always, the area will be less than 12.

There fore the answer should be C. Let me know if that the correct answer

Re: Is the area of the triangle ABC more than 12 sq. units? [#permalink]
05 May 2013, 02:47

The answer should be E As both the statements speak of only two sides of the triangle. But the area of any triangle with only 2 fixed sides can theoritically have a range between 0 to infinity to 1/2 A x B. Therefore both options should not be sufficient to answer the question. _________________

When you feel like giving up, remember why you held on for so long in the first place.

Last edited by aceacharya on 05 May 2013, 03:25, edited 1 time in total.

Re: Is the area of the triangle ABC more than 12 sq. units? [#permalink]
05 May 2013, 02:58

aceacharya wrote:

The answer should be E As both the statements speak of only two sides of the triangle. But the area of any triangle with only 2 fixed sides can theoritically have a range between 0 to infinity. Therefore both options should not be sufficient to answer the question.

Hi aceacharya, this is not quite true.

If you have 2 sides of a triangle (say 6 and 9) the gratest area you can obtain is the case in which those sides form a 90° angle. So in this case the greatest area is 6*9/2=27 (not infinite)

And also the area cannot be 0, otherwise the sides will "overlap" each other and we would have a line => not a triangle.

Hope this clarifies, let me know if you have doubts _________________

It is beyond a doubt that all our knowledge that begins with experience.

Re: Is the area of the triangle ABC more than 12 sq. units? [#permalink]
05 May 2013, 03:21

Zarrolou wrote:

aceacharya wrote:

The answer should be E As both the statements speak of only two sides of the triangle. But the area of any triangle with only 2 fixed sides can theoritically have a range between 0 to infinity. Therefore both options should not be sufficient to answer the question.

Hi aceacharya, this is not quite true.

If you have 2 sides of a triangle (say 6 and 9) the gratest area you can obtain is the case in which those sides form a 90° angle. So in this case the greatest area is 6*9/2=27 (not infinite)

And also the area cannot be 0, otherwise the sides will "overlap" each other and we would have a line => not a triangle.

Hope this clarifies, let me know if you have doubts

You're right. My Bad!! The maximum cant be infinity. The min however can tend to zero as the angle between the two tends to zero. _________________

When you feel like giving up, remember why you held on for so long in the first place.

Re: Is the area of the triangle ABC more than 12 sq. units? [#permalink]
06 May 2013, 01:30

Expert's post

1

This post was BOOKMARKED

OE :

The maximum area of a triangle for two given sides is when these two sides include a right angle.

From F.S 1, we know that GCD =2. All we know is that the sides are of the form 2a and 2b, where a and b are co-primes .Clearly Insufficient, as for different values of a and b, the area might/might not be more than 12 sq.units.

From F.S 2, we know that the LCM is 12. Thus, for sides as 1 and 12, we have the maximum area as\(\frac{1}{2}*1*12\) = 6 sq units, and it is not more than 12 sq.units. However for sides as 6 and 12, the maximum area is\(\frac{1}{2}*6*12\) = 36 sq. units, which is more than 12 sq.units. Insufficient.

Thus, combining both together, AB*BC = GCD*LCM = 2*12 = 24. Now, whatever values the sides take on, the product of the two sides will always be 24. Thus, the maximum area of this triangle =\(\frac{1}{2}*AB*BC\) = 12. Thus, as the maximum area for the given triangle is not more than 12, we have a definitive answer for the question.

Re: Is the area of the triangle ABC more than 12 sq. units? [#permalink]
01 Nov 2014, 01:07

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________

Hello everyone! Researching, networking, and understanding the “feel” for a school are all part of the essential journey to a top MBA. Wouldn’t it be great... ...

Are you interested in applying to business school? If you are seeking advice about the admissions process, such as how to select your targeted schools, then send your questions...

A lot of readers have asked me what benefits the Duke MBA has brought me. The MBA is a huge upfront investment and the opportunity cost is high. Most...