GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 19 Oct 2019, 11:23

### 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 rectangular coordinate system below, if OABC

Author Message
TAGS:

### Hide Tags

Intern
Joined: 21 Mar 2013
Posts: 38
GMAT Date: 03-20-2014
In the rectangular coordinate system below, if OABC  [#permalink]

### Show Tags

10 Jan 2014, 22:32
1
12
00:00

Difficulty:

95% (hard)

Question Stats:

31% (02:14) correct 69% (02:15) wrong based on 239 sessions

### HideShow timer Statistics

In the rectangular coordinate system below, if OABC is a parallelogram and OA > OC, is the area of OABC > 50 ?
Attachment:

(1) The coordinates of point C are (5, 5).

(2) The coordinates of point B are (0, 11).
Intern
Joined: 24 Apr 2012
Posts: 45
Re: In the rectangular coordinate system below, if OABC  [#permalink]

### Show Tags

11 Jan 2014, 00:02
1
1
See attached figure. CD is perpendicular to OB. Area of parallelogram OABC = OB x CD.

Statement 1:
OD = 5.
As, OA > OC, DB would have to be greater than 5. Hence OB > 5. Thus area of OABC > 50 (10 x 5)
Sufficient

Statement 2:
We know OB = 11, but have no idea about CD. Hence, we have no measure of area of OABC.
Insufficient

Solution: A

Regards
Mnemonic Education Pvt Ltd
ssingh@mnemoniceducation.com
_________________
www.mnemoniceducation.com

SVP
Joined: 06 Sep 2013
Posts: 1569
Concentration: Finance
Re: In the rectangular coordinate system below, if OABC  [#permalink]

### Show Tags

07 May 2014, 06:46
priyamne wrote:
See attached figure. CD is perpendicular to OB. Area of parallelogram OABC = OB x CD.

Statement 1:
OD = 5.
As, OA > OC, DB would have to be greater than 5. Hence OB > 5. Thus area of OABC > 50 (10 x 5)
Sufficient

Statement 2:
We know OB = 11, but have no idea about CD. Hence, we have no measure of area of OABC.
Insufficient

Solution: A

Regards
Mnemonic Education Pvt Ltd
ssingh@mnemoniceducation.com

First, why OD = 5? is the parallelogram symmetric across the y-axis? Also, I don't get how DB would have to be greater than 5.

Statement 2 is more clear

Thanks a lot buddy!
Cheers!
J
Math Expert
Joined: 02 Sep 2009
Posts: 58445
Re: In the rectangular coordinate system below, if OABC  [#permalink]

### Show Tags

07 May 2014, 08:43
jlgdr wrote:
priyamne wrote:

In the rectangular coordinate system below, if OABC is a parallelogram and OA > OC, is the area of OABC > 50 ?

(1) The coordinates of point C are (5, 5).

(2) The coordinates of point B are (0, 11).

See attached figure. CD is perpendicular to OB. Area of parallelogram OABC = OB x CD.

Statement 1:
OD = 5.
As, OA > OC, DB would have to be greater than 5. Hence OB > 5. Thus area of OABC > 50 (10 x 5)
Sufficient

Statement 2:
We know OB = 11, but have no idea about CD. Hence, we have no measure of area of OABC.
Insufficient

Solution: A

Regards
Mnemonic Education Pvt Ltd
ssingh@mnemoniceducation.com

First, why OD = 5? is the parallelogram symmetric across the y-axis? Also, I don't get how DB would have to be greater than 5.

Statement 2 is more clear

Thanks a lot buddy!
Cheers!
J

Attachment:

Untitled.png [ 7.84 KiB | Viewed 3478 times ]

(1) The coordinates of point C are (5, 5).

Why OD = 5? The y-coordinate of D is the same as that of C, so it's 5 --> OD = 5.

Is the parallelogram symmetric across the y-axis? It's not a mirror image around y-axis but the areas around it are the same.

Also, I don't get how DB would have to be greater than 5. Since BC = OA and OA > OC, then BC > OC. Thus BD > (OD=5).

Hope it's clear.
_________________
Manager
Joined: 02 Mar 2017
Posts: 71
GMAT 1: 700 Q51 V34
Re: In the rectangular coordinate system below, if OABC  [#permalink]

### Show Tags

20 Jun 2017, 08:11
Bunuel wrote:
jlgdr wrote:
priyamne wrote:

In the rectangular coordinate system below, if OABC is a parallelogram and OA > OC, is the area of OABC > 50 ?

(1) The coordinates of point C are (5, 5).

(2) The coordinates of point B are (0, 11).

See attached figure. CD is perpendicular to OB. Area of parallelogram OABC = OB x CD.

Statement 1:
OD = 5.
As, OA > OC, DB would have to be greater than 5. Hence OB > 5. Thus area of OABC > 50 (10 x 5)
Sufficient

Statement 2:
We know OB = 11, but have no idea about CD. Hence, we have no measure of area of OABC.
Insufficient

Solution: A

Regards
Mnemonic Education Pvt Ltd
ssingh@mnemoniceducation.com

First, why OD = 5? is the parallelogram symmetric across the y-axis? Also, I don't get how DB would have to be greater than 5.

Statement 2 is more clear

Thanks a lot buddy!
Cheers!
J

Attachment:
Untitled.png

(1) The coordinates of point C are (5, 5).

Why OD = 5? The y-coordinate of D is the same as that of C, so it's 5 --> OD = 5.

Is the parallelogram symmetric across the y-axis? It's not a mirror image around y-axis but the areas around it are the same.

Also, I don't get how DB would have to be greater than 5. Since BC = OA and OA > OC, then BC > OC. Thus BD > (OD=5).

Hope it's clear.

Little imagination helped me, but there is a calculation also to show how OB>10.

As we know that the BC is greater than OC ( property of ||gram- opposites sides equal), and by option A we fixed the point C (5,5)- imagine a ladder BC reclining on wall ( y-axis in this case)- and the only way the ladder can recline is if DB is greater than 5.

Calculation - I dont know how to draw a figure on GMAT forum, so I will use the above given figure and try to explain as much as possible-
Lets call Angle DOC = x = 45 Degree ( as Point C is 5,5 ) and angle OBC = y.

Now lets imagine BC is equal to OC. And hence <X=<Y = 45 Deg.

Therefore Triangle OBC is a right angled triangle.

Length of OC = BC = 5 sqt 2 ( \sqrt{5^2 + 5^2})
Therefore BO= \sqrt{OC^2 + BC^2}= 10 ( exactly)------ 1

But since BC > CO , therefore angle y < angle x = 45 Deg . Therefor Angle BCO >90 Deg ( In a triangle Angle OBC= 180 - x- y) ------2

Equation 1 and 2 tells that BO>10.

That ladder thing, I can explain if you require.
Non-Human User
Joined: 09 Sep 2013
Posts: 13277
Re: In the rectangular coordinate system below, if OABC  [#permalink]

### Show Tags

19 Dec 2018, 08:00
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 rectangular coordinate system below, if OABC   [#permalink] 19 Dec 2018, 08:00
Display posts from previous: Sort by