BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Is AB parallel to CD?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Legendary Member
Posts: 621
Joined: Wed Apr 09, 2008 7:13 pm
Thanked: 33 times
Followed by:4 members

Re: Is AB parallel to CD?

by vittalgmat » Sat Jul 18, 2009 12:15 am
madhur_ahuja wrote:Is AB parallel to CD?
(1) Angle a + angle b = 180º
(2) angle a + angle c + angle d + angle e = 360º
Pls post the OA within spoilers.


thanks
Top
Senior | Next Rank: 100 Posts
Posts: 36
Joined: Fri Mar 27, 2009 6:53 pm

by adamsmith2009 » Sat Jul 18, 2009 7:44 pm
D

Both statements are sufficient
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 157
Joined: Tue Oct 07, 2008 5:47 am
Thanked: 3 times

by PussInBoots » Sat Jul 18, 2009 7:58 pm
Sorry for offtopic, testing RSS feed filter
Top
Master | Next Rank: 500 Posts
Posts: 435
Joined: Sat May 02, 2009 3:55 am
Thanked: 17 times

by madhur_ahuja » Sat Jul 18, 2009 9:18 pm
adamsmith2009 wrote:D

Both statements are sufficient

How is I sufficient ?

IMO its B.
Top
Senior | Next Rank: 100 Posts
Posts: 49
Joined: Tue Jun 16, 2009 8:20 pm
Thanked: 5 times

by zenithexe » Sat Jul 18, 2009 9:45 pm
i agree with madhur, please look at the pic, that's perfectly valid considering the statement 1)
Attachments
Angle.jpg
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 434
Joined: Mon Jun 11, 2007 9:48 pm
Location: Bangalore
Thanked: 6 times
GMAT Score:600

by viju9162 » Sun Jul 19, 2009 12:40 am
How B is sufficient to answer the question ?
"Native of" is used for a individual while "Native to" is used for a large group
Top
Legendary Member
Posts: 752
Joined: Sun May 17, 2009 11:04 pm
Location: Tokyo
Thanked: 81 times
GMAT Score:680

Re: Is AB parallel to CD?

by tohellandback » Sun Jul 19, 2009 2:12 am
madhur_ahuja wrote:Is AB parallel to CD?
(1) Angle a + angle b = 180º
(2) angle a + angle c + angle d + angle e = 360º
IMO B
1) the two lines will be parallel when angle a+ angle c=180. (property)
angle c=180-angle b
when b=90, the lines are parallel, but in all other cases lines are not parallel.
NOT SUFF

2)angle a + angle c + angle d + angle e = 360º
angle d+ angle e=180
angle a + angle c=180
SUFF
The powers of two are bloody impolite!!
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 434
Joined: Mon Jun 11, 2007 9:48 pm
Location: Bangalore
Thanked: 6 times
GMAT Score:600

by viju9162 » Sun Jul 19, 2009 5:33 am
angle a + angle c = 180. Could you please explain this property which you have used to derive?

However, as I know, these are alternate angles and as per parallel lines property, when a transversal cuts the parallel lines, they form two pair of alternate angles.

How are we assuming these angles are supplementary?
"Native of" is used for a individual while "Native to" is used for a large group
Top
Legendary Member
Posts: 752
Joined: Sun May 17, 2009 11:04 pm
Location: Tokyo
Thanked: 81 times
GMAT Score:680

by tohellandback » Sun Jul 19, 2009 6:09 am
viju9162 wrote:angle a + angle c = 180. Could you please explain this property which you have used to derive?

However, as I know, these are alternate angles and as per parallel lines property, when a transversal cuts the parallel lines, they form two pair of alternate angles.

How are we assuming these angles are supplementary?
the property is "interior angles on the same side are supplementary"
plz check the image
Attachments
soln.JPG
The powers of two are bloody impolite!!
Top
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Thu May 28, 2015 12:24 am

by saakshig » Sun Jun 21, 2015 9:49 pm
Option a)
Angle a + angle b = 180.
Also since we can see that for any situation, angle b + angle c will be 180. (On the same line, supplementary).
This angle a + angle b = angle b + angle c.
Thus angle a = angle c. These are alternate angles. If they are equal lines are parallel.
SUFFICIENT

Option b)
Angles a + c + d + e = 360
d + e = 180 (supplementary)
Thus a + c = 180
Case 1: a=c=90. Lines will be parallel.
Case 2: for any other 2 values of a and c, a will not equal c. Hence not parallel.
INSUFFICIENT.

Answer is A.
Top
Post new topic Post Reply
• Page 1 of 1