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

 It is currently 18 Jul 2018, 21:12

### 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

# simplify

Author Message
Director
Joined: 25 Oct 2008
Posts: 548
Location: Kolkata,India

### Show Tags

09 Jun 2009, 20:33
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

If x = 4 and y = 16, then sq. root of (x+y/xy) is closest to which of the following ?

(A) 1/3
(B) 1/2
(C) 3/4
(D)7/8
(E) 1

[spoiler]OA:B[/spoiler]

Ok so i got stuck in the last step.Simplified and got sq root of 5/4.Now what if I have no clue of wat the value of sq root of 5 is?My ans was C because i know sq root of 4 is 2.So sq root of 5 should be a value 2+.I already have the denominator as 4.So C.CLearly the logic is wrong.

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.

_________________

http://gmatclub.com/forum/countdown-beginshas-ended-85483-40.html#p649902

Current Student
Joined: 03 Aug 2006
Posts: 112

### Show Tags

09 Jun 2009, 23:03
I think you were on the right track. For me I have memorized the sqrt of 2,3 and 5. The sqrt of 5 is 2.25. Hence answer is

$$\frac{2.25}{4} = \frac{9}{16}$$

which is closer to 1/2
Manager
Joined: 28 Jan 2004
Posts: 198
Location: India

### Show Tags

09 Jun 2009, 23:42
Just another way to look at it is....

by substituting X and Y we get .. Sqrt(5/16). Instead of performing square root of this , i will square the answer choices as squaring is easy.

1/3 give 1/9
1/2 gives 1/4
3/4 gives 9/16
7/8 gives 49/64
1 gives 1.

9/16 is closed to 5/16. So this should be answer. I am sure out of 5 atleast 3 will be definetly no-no for remianign 2 (if requird)you can perform a actual divide. This takes less time.
Director
Joined: 25 Oct 2008
Posts: 548
Location: Kolkata,India

### Show Tags

21 Jun 2009, 03:59
mdfrahim:i liked your approach but the OA is (b) not (c).NOW how do you explain?
_________________

http://gmatclub.com/forum/countdown-beginshas-ended-85483-40.html#p649902

Senior Manager
Joined: 08 Jan 2009
Posts: 310

### Show Tags

21 Jun 2009, 09:25
Agree with B

by substituting X and Y we get .. Sqrt(5/16) or 1/4 by Sqrt(5)

1/4 Sqrt(4) = 1/2 and 1/4 Sqrt(9) = 3/4 .

So our answer lie b/w this.

Scanning through the choice u will see A,D, E are out since outside our range.

Then among B and C . Definetly ours is closer to B.
Intern
Joined: 04 Mar 2008
Posts: 41

### Show Tags

22 Jun 2009, 16:56
tejal777 wrote:
If x = 4 and y = 16, then sq. root of (x+y/xy) is closest to which of the following ?

(A) 1/3
(B) 1/2
(C) 3/4
(D)7/8
(E) 1

[spoiler]OA:B[/spoiler]

Ok so i got stuck in the last step.Simplified and got sq root of 5/4.Now what if I have no clue of wat the value of sq root of 5 is?My ans was C because i know sq root of 4 is 2.So sq root of 5 should be a value 2+.I already have the denominator as 4.So C.CLearly the logic is wrong.

looks like you just missed the last step of the calculation.

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Re: simplify   [#permalink] 22 Jun 2009, 16:56
Display posts from previous: Sort by

# Events & Promotions

 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®.