GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

 It is currently 30 Mar 2020, 12:43

### 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

# In the figure above, if O is the center of the circle, which of the fo

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 62353
In the figure above, if O is the center of the circle, which of the fo  [#permalink]

### Show Tags

11 Dec 2017, 22:08
00:00

Difficulty:

25% (medium)

Question Stats:

78% (01:24) correct 23% (01:33) wrong based on 80 sessions

### HideShow timer Statistics

In the figure above, if O is the center of the circle, which of the following points lies outside the circle?

(A) (–7, –8)
(B) (–7, 7)
(C) (8, –6)
(D) (8, 5)
(E) (9, 4)

Attachment:

2017-12-12_1001_002.png [ 7.87 KiB | Viewed 1332 times ]

_________________
Senior SC Moderator
Joined: 22 May 2016
Posts: 3667
Re: In the figure above, if O is the center of the circle, which of the fo  [#permalink]

### Show Tags

12 Dec 2017, 08:09
1
Bunuel wrote:

In the figure above, if O is the center of the circle, which of the following points lies outside the circle?

(A) (–7, –8)
(B) (–7, 7)
(C) (8, –6)
(D) (8, 5)
(E) (9, 4)

Attachment:
2017-12-12_1001_002.png

One quick way to approach this question: add the squares of the coordinates in the answers. They should not be greater than 100. (I avoid the distance formula when there are less error-prone ways to solve.)

The general equation for a line is $$x^2 + y^2 = r^2$$.

This circle's radius is 10 (center x-coordinate is at 0, a point on the circle is (10,0), subtract x-coordinates).

So this line's equation is $$x^2 + y^2 = 100$$.

A point outside the circle will have coordinates whose squares sum to more than 100.

$$x^2 + y^2 = 100$$

(A) (–7, –8)
$$(-7)^2 + 8^2 = 49 + 64 = 113$$
Outside the circle. Keep

(B) (–7, 7)
$$49 + 49 = 98$$. Inside the circle. Reject

(C) (8, –6)
$$64 + 36 = 100$$. On the circle. Reject

(D) (8, 5)
$$64 + 25 = 89$$. Inside the circle. Reject

(E) (9, 4)
$$81 + 16 = 97$$. Inside the circle. Reject

_________________
Visit SC Butler, here! Get two SC questions to practice, whose links you can find by date.

Never doubt that a small group of thoughtful, committed citizens can change the world; indeed, it's the only thing that ever has. -- Margaret Mead
Non-Human User
Joined: 09 Sep 2013
Posts: 14448
Re: In the figure above, if O is the center of the circle, which of the fo  [#permalink]

### Show Tags

09 Feb 2020, 08:12
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.
_________________
Re: In the figure above, if O is the center of the circle, which of the fo   [#permalink] 09 Feb 2020, 08:12
Display posts from previous: Sort by