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

It is currently 19 Nov 2018, 08:31

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.

Close

Request Expert Reply

Confirm Cancel
Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
  • How to QUICKLY Solve GMAT Questions - GMAT Club Chat

     November 20, 2018

     November 20, 2018

     09:00 AM PST

     10:00 AM PST

    The reward for signing up with the registration form and attending the chat is: 6 free examPAL quizzes to practice your new skills after the chat.
  • The winning strategy for 700+ on the GMAT

     November 20, 2018

     November 20, 2018

     06:00 PM EST

     07:00 PM EST

    What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.

What is the area of the above triangle?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6526
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
What is the area of the above triangle?  [#permalink]

Show Tags

New post 06 Sep 2018, 00:33
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

83% (00:40) correct 17% (00:51) wrong based on 47 sessions

HideShow timer Statistics

[Math Revolution GMAT math practice question]

Attachment:
9.6.png
9.6.png [ 2.2 KiB | Viewed 584 times ]


What is the area of the above triangle?

\(1) y=z\)
\(2) y+z=10\)

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Senior Manager
Senior Manager
User avatar
P
Joined: 18 Jul 2018
Posts: 374
Location: India
Concentration: Finance, Marketing
WE: Engineering (Energy and Utilities)
Premium Member CAT Tests
Re: What is the area of the above triangle?  [#permalink]

Show Tags

New post 06 Sep 2018, 01:23
From statement 1:

The triangle can be an equilateral or isosceles triangle depending on the value of X.
Hence Insufficient.

From statement 2:

No info about the other side X.
Hence insufficient.

Combining both will not give any new info.

Hence E is the answer.
_________________

When you want something, the whole universe conspires in helping you achieve it.

GMATH Teacher
User avatar
G
Status: GMATH founder
Joined: 12 Oct 2010
Posts: 480
What is the area of the above triangle?  [#permalink]

Show Tags

New post 06 Sep 2018, 05:57
MathRevolution wrote:
[Math Revolution GMAT math practice question]

What is the area of the above triangle?

\(1) y=z\)
\(2) y+z=10\)


Let´s go straight to (1+2) . Reason: if we are able to (geometrically) BIFURCATE both statements together immediately, we save a significant amount of time!

The areas of both triangles presented are different, and both triangles satisfy both statements. We are done: the answer is (E).

This solution follows the notations and rationale taught in the GMATH method.

Regards,
fskilnik.
Attachments

06Set18_13z.gif
06Set18_13z.gif [ 23.86 KiB | Viewed 553 times ]


_________________

Fabio Skilnik :: https://GMATH.net (Math for the GMAT) or GMATH.com.br (Portuguese version)
Course release PROMO : finish our test drive till 30/Nov with (at least) 50 correct answers out of 92 (12-questions Mock included) to gain a 50% discount!

Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6526
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
Re: What is the area of the above triangle?  [#permalink]

Show Tags

New post 09 Sep 2018, 17:22
=>

Forget conventional ways of solving math questions. For DS problems, the VA (Variable Approach) method is the quickest and easiest way to find the answer without actually solving the problem. Remember that equal numbers of variables and independent equations ensure a solution.

Since we have 3 variables (x, y and z) and 0 equations, E is most likely to be the answer. So, we should consider conditions 1) & 2) together first. After comparing the number of variables and the number of equations, we can save time by considering conditions 1) & 2) together first.

Conditions 1) & 2)

Attachment:
9.10.png
9.10.png [ 13.33 KiB | Viewed 469 times ]


If \(x = y = z = 5\), then the triangle is equilateral, and its area is \((\frac{√3}{4})*52 = (\frac{25}{4}) √3\).
If \(x = 6\) and \(y = z = 5\), then the area of the triangle is \((\frac{1}{2})6*4 = 12.\)
Since the answer is not unique, conditions 1) & 2) are not sufficient, when taken together.

Therefore, E is the answer.
Answer: E

In cases where 3 or more additional equations are required, such as for original conditions with “3 variables”, or “4 variables and 1 equation”, or “5 variables and 2 equations”, conditions 1) and 2) usually supply only one additional equation. Therefore, there is an 80% chance that E is the answer, a 15% chance that C is the answer, and a 5% chance that the answer is A, B or D. Since E (i.e. conditions 1) & 2) are NOT sufficient, when taken together) is most likely to be the answer, it is generally most efficient to begin by checking the sufficiency of conditions 1) and 2), when taken together. Obviously, there may be occasions on which the answer is A, B, C or D.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

GMAT Club Bot
Re: What is the area of the above triangle? &nbs [#permalink] 09 Sep 2018, 17:22
Display posts from previous: Sort by

What is the area of the above triangle?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.