Last visit was: 29 May 2026, 12:10 It is currently 29 May 2026, 12:10
Home
Messages
MBA Fair
Tests
Schools
Events
Close
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
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
805+ (Hard)|   Geometry|      
User avatar
figjam786
User avatar
Joined: 25 May 2020
Last visit: 08 Nov 2023
Posts: 50
Own Kudos:
238
 [4]
Given Kudos: 37
Posts: 50
Kudos: 238
 [4]
What is value of X in given figure. 21 Jul 2022, 08:38
1
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

95% (hard)

Question Stats:

0% (00:00) correct 100% (01:46) wrong based on 16 sessions

History

Date
Time
Result
Not Attempted Yet
What is value of \(X\) in given figure.


a) 7
b) 8
c) \(\sqrt{71}\)
d) \(\sqrt{80}\)
e) 9
ShowHide Answer
Official Answer
C

Attachments

Screenshot 2022-07-21 204950.png
Screenshot 2022-07-21 204950.png [ 40.25 KiB | Viewed 1357 times ]

User avatar
ksyed
User avatar
Joined: 06 Jul 2022
Last visit: 30 Dec 2022
Posts: 7
Own Kudos:
4
Given Kudos: 64
GMAT 1: 750 Q50 V41
GPA: 3.73
Products:
My Reviews
GMAT 1: 750 Q50 V41
Posts: 7
Kudos: 4
What is value of X in given figure. 22 Jul 2022, 08:51
Kudos
Add Kudos
Bookmarks
Bookmark this Post
How could the answer be C, please explain?
User avatar
figjam786
User avatar
Joined: 25 May 2020
Last visit: 08 Nov 2023
Posts: 50
Own Kudos:
238
Given Kudos: 37
Posts: 50
Kudos: 238
What is value of X in given figure. 22 Jul 2022, 09:08
Kudos
Add Kudos
Bookmarks
Bookmark this Post
ksyed
How could the answer be C, please explain?
Show more


ThatDudeKnows > can u help?

Posted from my mobile device
User avatar
ThatDudeKnows
User avatar
Joined: 11 May 2022
Last visit: 27 Jun 2024
Posts: 1,070
Own Kudos:
1,038
 [1]
Given Kudos: 79
Expert
Expert reply
Posts: 1,070
Kudos: 1,038
 [1]
What is value of X in given figure. Updated on: 22 Jul 2022, 11:19
Originally posted by ThatDudeKnows on 22 Jul 2022, 09:24.
Last edited by ThatDudeKnows on 22 Jul 2022, 11:19, edited 5 times in total.
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
figjam786
What is value of \(X\) in given figure.


a) 7
b) 8
c) \(\sqrt{71}\)
d) \(\sqrt{80}\)
e) 9
Show more

figjam786
ksyed
Mohammadmo

I think the first instinct is to sketch in a couple extra lines as in the attached figure. But once you do that, you can see that by labeling one of the angles a and the complementary angle b, you end up with two 3-4-5 triangles, one of which has the 3 opposite angle a and the other of which has the 4 opposite angle a. We can't do that! So, we know that the figure is drawn out of scale and that point at the bottom middle is NOT actually on a horizontal line created by making a rectangle!

I've redrawn the figure closer to scale and added a few extra points and lines.

Looking at triangle ACF, we have
\(4^2 + 8^2 = AC^2\)
\(16 + 64 = AC^2\)
\(80 = AC^2\)
\(AC = \sqrt{80}\)

Now looking at triangle ABC, we have
\(3^2 + AB^2 = \sqrt{80}^2\)
\(9 + AB^2 = 80\)
\(AB^2 = 71\)
\(AB = \sqrt{71}\)

Answer choice C.
Attachments

Picture4.png
Picture4.png [ 127.63 KiB | Viewed 1145 times ]

Picture3.png
Picture3.png [ 22.84 KiB | Viewed 1139 times ]

User avatar
Mohammadmo
User avatar
Joined: 29 Jun 2019
Last visit: 03 Nov 2022
Posts: 346
Own Kudos:
250
Given Kudos: 16
Posts: 346
Kudos: 250
What is value of X in given figure. 22 Jul 2022, 10:11
Kudos
Add Kudos
Bookmarks
Bookmark this Post
I don't understand why the answer is not 9 ?!

Posted from my mobile device
Moderator:
Bunuel
Math Expert
110897 posts