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

 It is currently 18 Oct 2019, 04:42

### 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, AD and BC are lines intersecting at O. What is the valu

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58458
In the figure, AD and BC are lines intersecting at O. What is the valu  [#permalink]

### Show Tags

Updated on: 15 Jul 2019, 04:11
00:00

Difficulty:

35% (medium)

Question Stats:

74% (02:11) correct 26% (02:35) wrong based on 39 sessions

### HideShow timer Statistics

In the figure, AD and BC are lines intersecting at O. What is the value of a ?

(A) 15

(B) 30

(C) 45

(D) 60

(E) 135

Source: Nova GMAT
Difficulty Level: 600

Attachment:

lines (1).jpg [ 20.85 KiB | Viewed 769 times ]

_________________

Originally posted by Bunuel on 09 Oct 2018, 01:03.
Last edited by SajjadAhmad on 15 Jul 2019, 04:11, edited 1 time in total.
CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2978
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: In the figure, AD and BC are lines intersecting at O. What is the valu  [#permalink]

### Show Tags

09 Oct 2018, 03:22
Bunuel wrote:

In the figure, AD and BC are lines intersecting at O. What is the value of a ?

(A) 15
(B) 30
(C) 45
(D) 60
(E) 135

Attachment:
lines (4).jpg

Vertically Opposite angles are equal
5x + 5a = 5y/2

i.e. 2x + 2a = y

Also, 5x + 5a + 2x + 30 = 180

i.e. 7x + 5a = 150

Also, y = 2x + 30

i.e. 2x + 2a = 2x + 30

i.e. a = 15

_________________
Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
Manager
Joined: 08 Sep 2008
Posts: 134
Location: India
Concentration: Operations, General Management
Schools: ISB '20
GPA: 3.8
WE: Operations (Transportation)
Re: In the figure, AD and BC are lines intersecting at O. What is the valu  [#permalink]

### Show Tags

09 Oct 2018, 04:37
Bunuel wrote:

In the figure, AD and BC are lines intersecting at O. What is the value of a ?

(A) 15
(B) 30
(C) 45
(D) 60
(E) 135

Attachment:
lines (4).jpg

5x+5a=5y/2
2x+30=y

Substitute value of y

10x+10a= 10x+150
10a=150
A=15

Sent from my iPad using GMAT Club Forum mobile app
_________________
Regards;
Vishal

+==========+
Kudos if it deserve....one...
VP
Status: Learning stage
Joined: 01 Oct 2017
Posts: 1013
WE: Supply Chain Management (Energy and Utilities)
Re: In the figure, AD and BC are lines intersecting at O. What is the valu  [#permalink]

### Show Tags

09 Oct 2018, 17:43
Bunuel wrote:

In the figure, AD and BC are lines intersecting at O. What is the value of a ?

(A) 15

(B) 30

(C) 45

(D) 60

(E) 135

a) $$y+\frac{5y}{2}=180$$ or, y=360/7 (Angles on one side of a straight line always add to 180 degrees)
b) y=2x+30 or, $$x=\frac{75}{7}$$ (opposite angles are congruent)
c) 5x+5a+2x+30=180 or, 7x+5a=150 or, 5a=150-75=75 or, a=15

Ans. (A)
_________________
Regards,

PKN

Rise above the storm, you will find the sunshine
Director
Joined: 27 May 2012
Posts: 901
Re: In the figure, AD and BC are lines intersecting at O. What is the valu  [#permalink]

### Show Tags

16 Oct 2018, 00:51
1
Bunuel wrote:

In the figure, AD and BC are lines intersecting at O. What is the value of a ?

(A) 15
(B) 30
(C) 45
(D) 60
(E) 135

Attachment:
lines (4).jpg

Dear Moderator,
Same question seems to have been duplicated in the link below , you may wish to merge the same, Thank you.

https://gmatclub.com/forum/in-the-figur ... l#p2148445
_________________
- Stne
Math Expert
Joined: 02 Sep 2009
Posts: 58458
Re: In the figure, AD and BC are lines intersecting at O. What is the valu  [#permalink]

### Show Tags

16 Oct 2018, 00:53
stne wrote:
Bunuel wrote:

In the figure, AD and BC are lines intersecting at O. What is the value of a ?

(A) 15
(B) 30
(C) 45
(D) 60
(E) 135

Attachment:
lines (4).jpg

Dear Moderator,
Same question seems to have been duplicated in the link below , you may wish to merge the same, Thank you.

https://gmatclub.com/forum/in-the-figur ... l#p2148445

________________
Merged. Thank you.
_________________
Intern
Joined: 08 Oct 2018
Posts: 3
Re: In the figure, AD and BC are lines intersecting at O. What is the valu  [#permalink]

### Show Tags

16 Oct 2018, 10:39
we can say, 5x+5a=5y/2
=>5(x+a)=5y/2
=>2x+2a=y

again, y=2x+30
=>2x+2a=2x+30
=>a=15
Ans A

Posted from my mobile device
Re: In the figure, AD and BC are lines intersecting at O. What is the valu   [#permalink] 16 Oct 2018, 10:39
Display posts from previous: Sort by