Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 02 Jul 2015, 10:19

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Square roots

Author Message
TAGS:
Senior Manager
Joined: 10 Mar 2008
Posts: 375
Followers: 4

Kudos [?]: 102 [0], given: 0

Square roots [#permalink]  03 Oct 2008, 11:06
Attachments

question1.jpg [ 8.79 KiB | Viewed 1132 times ]

Director
Joined: 27 Jun 2008
Posts: 547
WE 1: Investment Banking - 6yrs
Followers: 1

Kudos [?]: 48 [0], given: 92

Re: Square roots [#permalink]  03 Oct 2008, 11:29
D

I must confess, it took me a while to solve this, however, if its a "GMAT" problem, you should be able to solve it within 2 mins. So, I was rattling my brian.

Anyway, rt63 = 3rt7.

> ROOT 2rt63 + 2 / 8+rt63
> ROOT 8*2rt63 + rt63*rt63*2 + 2 / 8+rt63
> ROOT 16rt63 + 128 / 8+rt63
> ROOT 16(rt63 + 8) / (8 + rt63)
> ROOT 16 = 4
Manager
Joined: 27 Sep 2008
Posts: 76
Followers: 1

Kudos [?]: 7 [0], given: 0

Re: Square roots [#permalink]  03 Oct 2008, 11:36
we know that 8+sqrt(63)/8+sqrt(63) = 1

so:

sqrt(2sqrt(63)+2/8+3*sqrt(7)) = x

2*sqrt(63)+2/8+3*sqrt(7) = x^2

2*sqrt(63)*1+2/8+sqrt(63) = x^2

2*sqrt(63)*(8+sqrt(63)/8+sqrt(63))+2/8+sqrt(63) = x^2

(2*sqrt(63)*(8+sqrt(63))+2)/8+sqrt(63) = x^2

(16*sqrt(63)+63*2+2)/8+sqrt(63) = x^2

16*sqrt(63)+128/8+sqrt(63) = x^2

16*(sqrt(63)+8)/(8+sqrt(63)) = x^2

16*1 = x^2

x = 4

Manager
Joined: 24 Aug 2008
Posts: 230
Location: India
WE 1: 3.75 IT
WE 2: 1.0 IT
Followers: 2

Kudos [?]: 34 [0], given: 5

Re: Square roots [#permalink]  06 Oct 2008, 01:42

And the calculation was even not that complex. You can solve it directly.
_________________

Cheers,
Varun

If you like my post, give me KUDOS!!

SVP
Joined: 05 Jul 2006
Posts: 1516
Followers: 5

Kudos [?]: 124 [0], given: 39

Re: Square roots [#permalink]  06 Oct 2008, 02:01
vksunder wrote:

if GMAT is for business leaders , i will think like one and use approximation

sqrt(2sqrt63 + 2 / 8+3sqrt7)

sqrt 63 = approximately sqrt 64 = 8

sqrt 7 approx = sqrt 9 = 3

sqrt ( 2*8 + 2 / 3*3) = sqrt (16 + 2 /17) = sqrt ( 274/ 16) = sqrt 274 / sqrt 16 =

approx sqrt ( 16^2) / sqrt 16 = 16/4 = 4
Senior Manager
Joined: 10 Mar 2008
Posts: 375
Followers: 4

Kudos [?]: 102 [0], given: 0

Re: Square roots [#permalink]  06 Oct 2008, 05:05
Very Good point yezz. Damn, I need to start thinking like a leader:)
Re: Square roots   [#permalink] 06 Oct 2008, 05:05
Similar topics Replies Last post
Similar
Topics:
Square root 8 14 Oct 2008, 23:12
square root 5 25 Aug 2006, 07:27
SQUARE ROOT 3 22 Jul 2006, 12:07
Squares and Roots 3 26 Apr 2006, 07:27
Square root 4 24 Nov 2005, 15:54
Display posts from previous: Sort by