Math questions from any Manhattan Prep GMAT Computer Adaptive Test.
rkkarthik
Course Students
 
Posts: 15
Joined: Tue Dec 22, 2009 5:20 am
 

Manhattan GMAT (Timing Lab) Question -Approach clarification

by rkkarthik Fri Nov 19, 2010 11:44 pm

Hello there,

Slide 8 of the timing lab explains a challenge question.

I was able to solve it by estimation and picking numbers.

However I would like to get my approach validated as I am notorious for mathematical calculation, and approach errors.

As the question involves notations such as square root,
I created white board to make it easier on the eyes.

Kindly review and suggest alternative approach if I am way off.

Image
http://img824.imageshack.us/i/questionchallenge.jpg

Note: BTW my answer was correct!
Karthik
atul.prasad
Students
 
Posts: 34
Joined: Thu Sep 09, 2010 8:57 pm
 

Re: Manhattan GMAT (Timing Lab) Question -Approach clarification

by atul.prasad Sat Nov 20, 2010 8:38 am

The question is :

sqrt [sqrt(96) + 2/(5+2*sqrt(6))]
which can be written as:

sqrt[4*sqrt(6) + (2*(5-2*sqrt(6))/((5-2*sqrt(6)) * (5+2*sqrt(6))]
<multiplying the both the numerator and denominator of 2nd term by 5-2*sqrt(6)>

=> sqrt[4*sqrt(6) + (10 - 4*sqrt(6))/1]

=> sqrt(10)
rkkarthik
Course Students
 
Posts: 15
Joined: Tue Dec 22, 2009 5:20 am
 

Re: Manhattan GMAT (Timing Lab) Question -Approach clarification

by rkkarthik Sat Nov 20, 2010 10:52 am

I was not necessarily asking for a way to solve it, but was looking for a validation of my approach. But again, Thanks for your time!

(Please consider this post closed) - The Lab had an explanation which re-affirmed my position. Thanks

KK
jnelson0612
ManhattanGMAT Staff
 
Posts: 2664
Joined: Fri Feb 05, 2010 10:57 am
 

Re: Manhattan GMAT (Timing Lab) Question -Approach clarification

by jnelson0612 Sat Nov 20, 2010 9:49 pm

Okay, thank you.
Jamie Nelson
ManhattanGMAT Instructor