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

It is currently 23 Jan 2019, 22:38

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 January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
  • Key Strategies to Master GMAT SC

     January 26, 2019

     January 26, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.
  • Free GMAT Number Properties Webinar

     January 27, 2019

     January 27, 2019

     07:00 AM PST

     09:00 AM PST

    Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes.

4^(1/4) =

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

Hide Tags

 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52437
4^(1/4) =  [#permalink]

Show Tags

New post 10 Apr 2018, 20:58
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

70% (00:40) correct 30% (01:07) wrong based on 127 sessions

HideShow timer Statistics

examPAL Representative
User avatar
G
Joined: 07 Dec 2017
Posts: 868
Re: 4^(1/4) =  [#permalink]

Show Tags

New post 10 Apr 2018, 22:13
Bunuel wrote:
\(\sqrt[4]{4}\) is:

A. Less than 0.8
B. Between 0.8 and 1.2
C. Between 1.2 and 1.6
D. Between 1.6 and 2.0
E. Greater than 2.0


We'll show two solutions:

The Precise, equation-driven approach involves simplifying our given data:
\(\sqrt[4]{4}=4^\frac{1}{4}=(2^2)^\frac{1}{4}=2^{2*\frac{1}{4}}=2^\frac{1}{2}=\sqrt{2}\).
As the square root of 2 is about 1.4 (you should know this by heart), our answer is (C).

The Alternative approach involves estimating and eliminating impossible answers:
1^4 = 1 so \(\sqrt[4]{4}\) must be larger than 1. (A) is eliminated.
Let's try 1.2: 1.2^2 = 1.44 and (1.44)^2 is less than 4. So our answer is larger than 1.2. (B) is eliminated.
Let's try 1.6: 1.6^2 = 2.56 and (2.56)^2 is more than 4. So our answer is smaller than 1.6. (D), (E) are eliminated.
(Note that 1.2^2 = (12^2)/100 and 1.6^2 = (16^2)/100. You should know these as part of the basic powers)

(C) is our answer.
_________________

Image
Sign up for 7-day free trial
Image

Image

Crack the GMAT with the complete 2019 bundle:


Online course + Boot camp training + GMAT Club tests + Unlimited support and save 25% on any GMAT course!

Valid until Jan 31st at 23:55 PST.

Choose my course

CEO
CEO
User avatar
D
Joined: 11 Sep 2015
Posts: 3360
Location: Canada
Re: 4^(1/4) =  [#permalink]

Show Tags

New post 11 Apr 2018, 03:56
Top Contributor
Bunuel wrote:
\(\sqrt[4]{4}\) is:

A. Less than 0.8
B. Between 0.8 and 1.2
C. Between 1.2 and 1.6
D. Between 1.6 and 2.0
E. Greater than 2.0


All GMAT students should memorize the following square roots before test day:
√2 ≈ 1.4
√3 ≈ 1.7
√5 ≈ 2.2

If we do so, then this question is quite manageable.

\(\sqrt[4]{4}\) = 4^(1/4)
If we rewrite 4 as ...
...we get: 4^(1/4) = ^(1/4)
= 2^(1/2) [applied the power of a power law]
= √2
≈ 1.4

Answer: C

RELATED VIDEO

_________________

Test confidently with gmatprepnow.com
Image

Target Test Prep Representative
User avatar
P
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 4612
Location: United States (CA)
Re: 4^(1/4) =  [#permalink]

Show Tags

New post 12 Apr 2018, 15:19
Bunuel wrote:
\(\sqrt[4]{4}\) is:

A. Less than 0.8
B. Between 0.8 and 1.2
C. Between 1.2 and 1.6
D. Between 1.6 and 2.0
E. Greater than 2.0


The fourth root of 4 is the same thing as taking the square root of 4 and then taking the square root of that answer. Thus:

√4 = 2 and √2 ≈ 1.4

So the 4th root of 4 is approximately 1.4, which is between 1.2 and 1.6.

Answer: C
_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

GMAT Club Bot
Re: 4^(1/4) = &nbs [#permalink] 12 Apr 2018, 15:19
Display posts from previous: Sort by

4^(1/4) =

  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®.