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 500,000 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:

As per the below diagram, lets say a circle is passing through AOC. angle AOC = angle AEC, so, irrespective of the fact that O is center or not, it is possible to have any angle as twice of angle ABC.

Thus, even after combining the two statement we can't figure out whether O is center of the circle.

Remember, the angle subtended by arc at the center is twice of the angle subtended by the arc on rest of the circumference but the converse is not true.

Re: What is the area of circle passing points A, B & C (in the [#permalink]

Show Tags

25 Jun 2012, 19:53

cyberjadugar wrote:

What is the area of circle passing points A, B & C (in the given figure), if the angle ABC is 60?

(1) Angle AOC is 120. (2) OA is 6 units.

I was supposed to answer B. But that is wrong, why? Because the sufficiency of answer B is pivoted on the assumption that O is indeed the center of the circle. But, this is not the case. The question doesn't tell us that O is the center of the circle. This is a very good assumption/data sufficiency question. It doesn't necessarily mean that ABC is 60 that AOC is already 120. That'd be a wrong assumption. What is OA is an arc? or OA is a line segment not connected to the center?

Now, as like what the poster said above, we need A to prove that O is the center. Now that we know O is the center and from (2) we know that OA is 6 units, we know that the radius of the circle is 6. From that we can know the area of the circle.
_________________

Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure... than to rank with those poor spirits who neither enjoy nor suffer much, because they live in a gray twilight that knows not victory nor defeat. - T. Roosevelt

Re: What is the area of circle passing points A, B & C (in the [#permalink]

Show Tags

25 Jun 2012, 20:16

gmatsaga wrote:

cyberjadugar wrote:

What is the area of circle passing points A, B & C (in the given figure), if the angle ABC is 60?

(1) Angle AOC is 120. (2) OA is 6 units.

I was supposed to answer B. But that is wrong, why? Because the sufficiency of answer B is pivoted on the assumption that O is indeed the center of the circle. But, this is not the case. The question doesn't tell us that O is the center of the circle. This is a very good assumption/data sufficiency question. It doesn't necessarily mean that ABC is 60 that AOC is already 120. That'd be a wrong assumption. What is OA is an arc? or OA is a line segment not connected to the center?

Now, as like what the poster said above, we need A to prove that O is the center. Now that we know O is the center and from (2) we know that OA is 6 units, we know that the radius of the circle is 6. From that we can know the area of the circle.

Hi,

Again, a little more thinking required...and I would say it's safe to assume OA is line segment.

Re: What is the area of circle passing points A, B & C (in the [#permalink]

Show Tags

27 Jun 2012, 00:17

cyberjadugar wrote:

Posted the OA in the question.

Regards,

Can you explain why (E) is the answer?
_________________

Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure... than to rank with those poor spirits who neither enjoy nor suffer much, because they live in a gray twilight that knows not victory nor defeat. - T. Roosevelt

Campus visits play a crucial role in the MBA application process. It’s one thing to be passionate about one school but another to actually visit the campus, talk...

Its been long time coming. I have always been passionate about poetry. It’s my way of expressing my feelings and emotions. And i feel a person can convey...

Marty Cagan is founding partner of the Silicon Valley Product Group, a consulting firm that helps companies with their product strategy. Prior to that he held product roles at...

Written by Scottish historian Niall Ferguson , the book is subtitled “A Financial History of the World”. There is also a long documentary of the same name that the...