BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Simplying Exponents And Dividing

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Sun Feb 26, 2012 7:57 pm
RyanP wrote:(8^2)(3^3)(2^4)/(96^2)=

A = 3
B = 6
C = 9
D = 12
E = 18

I tried to read through this post here: https://www.beatthegmat.com/can-someone- ... 16619.html but I just don't understand the math.
96 = 2^5 * 3

(8^2)(3^3)(2^4)/(96^2) = (2^3)^2 * (3^3) * (2^4)/(2^5 * 3)^2
= (2^6) * (3^3) * (2^4)/(2^10 * 3²)
= (2^10) * (3^3))/(2^10 * 3²)
= 3

The correct answer is A.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top
Junior | Next Rank: 30 Posts
Posts: 15
Joined: Mon Feb 20, 2012 6:32 pm

by RyanP » Fri Mar 02, 2012 2:19 pm
Anurag@Gurome wrote:
(8^2)(3^3)(2^4)/(96^2) = (2^3)^2 * (3^3) * (2^4)/(2^5 * 3)^2
= (2^6) * (3^3) * (2^4)/(2^10 * 3²)
= (2^10) * (3^3))/(2^10 * 3²)
= 3

The correct answer is A.
I don't understand how you reduce 96^2 to (2^5*3)^2. 96*96 = 9216. (64*3)^2 = 36864. Am I missing something? How are those equivalent?
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 143
Joined: Mon Mar 14, 2011 3:13 am
Thanked: 34 times
Followed by:5 members

by krusta80 » Fri Mar 02, 2012 4:52 pm
RyanP wrote:(8^2)(3^3)(2^4)/(96^2)=

A = 3
B = 6
C = 9
D = 12
E = 18

I tried to read through this post here: https://www.beatthegmat.com/can-someone- ... 16619.html but I just don't understand the math.
This is really just an exercise in breaking down 96 into a product of primes:

96 = 2^5 * 3^1

Let's also do the same for 8:

8 = 2^3

Applying this to the problem at hand...

(8^2)(3^3)(2^4)/(96^2)=((2^3)^2)(3^3)(2^4)/((2^5 * 3^1)^2)=(2^10)(3^3)/[(2^10)(3^2)]

Now we can start cancelling out terms:

(3^3)(2^10)/[(2^10)(3^2)] = 3


Answer is A
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 143
Joined: Mon Mar 14, 2011 3:13 am
Thanked: 34 times
Followed by:5 members

by krusta80 » Fri Mar 02, 2012 4:53 pm
RyanP wrote:
Anurag@Gurome wrote:
(8^2)(3^3)(2^4)/(96^2) = (2^3)^2 * (3^3) * (2^4)/(2^5 * 3)^2
= (2^6) * (3^3) * (2^4)/(2^10 * 3²)
= (2^10) * (3^3))/(2^10 * 3²)
= 3

The correct answer is A.
I don't understand how you reduce 96^2 to (2^5*3)^2. 96*96 = 9216. (64*3)^2 = 36864. Am I missing something? How are those equivalent?
2^5 is 32, not 64 :)
Top
Post new topic Post Reply
• Page 1 of 1