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

Redeem

PS - Exponent

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 » Tue Dec 13, 2011 7:34 pm
karthikpandian19 wrote:See the attached figure for ref.
Image

R = 3^81

R^R = 3^S

What is S?

a. 3
b. 81
c. 3^81
d. 3^85
e. 3^87
R = 3^81
(3^81)^(3^81) = 3^S
[3^(3^4)]^(3^81) = 3^S
[3^(3^85)] = 3^S
Since bases are same, so exponents will also be equal.
Hence, S = [spoiler]3^85[/spoiler]

The correct answer is D.
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
User avatar
Legendary Member
Posts: 1665
Joined: Thu Nov 03, 2011 7:04 pm
Thanked: 165 times
Followed by:70 members

by karthikpandian19 » Tue Dec 13, 2011 10:26 pm
Anurag,

I am still unable to understand your answer.....from


R = 3^81
(3^81)^(3^81) = 3^S
[3^(3^4)]^(3^81) = 3^S......how it is proceeded to the next step
[3^(3^85)] = 3^S
Since bases are same, so exponents will also be equal.
Hence, S = [spoiler]3^85[/spoiler]


Anurag@Gurome wrote:
karthikpandian19 wrote:See the attached figure for ref.
Image

R = 3^81

R^R = 3^S

What is S?

a. 3
b. 81
c. 3^81
d. 3^85
e. 3^87
R = 3^81
(3^81)^(3^81) = 3^S
[3^(3^4)]^(3^81) = 3^S
[3^(3^85)] = 3^S
Since bases are same, so exponents will also be equal.
Hence, S = [spoiler]3^85[/spoiler]

The correct answer is D.
Top

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 » Wed Dec 14, 2011 2:53 am
karthikpandian19 wrote:Anurag,

I am still unable to understand your answer.....from


R = 3^81
(3^81)^(3^81) = 3^S
[3^(3^4)]^(3^81) = 3^S......how it is proceeded to the next step
[3^(3^85)] = 3^S
Since bases are same, so exponents will also be equal.
Hence, S = [spoiler]3^85[/spoiler]
Image
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
User avatar
Legendary Member
Posts: 1665
Joined: Thu Nov 03, 2011 7:04 pm
Thanked: 165 times
Followed by:70 members

by karthikpandian19 » Thu Dec 15, 2011 12:48 am
Thank you for your explanation, now i understood.....
Anurag@Gurome wrote:
karthikpandian19 wrote:Anurag,

I am still unable to understand your answer.....from


R = 3^81
(3^81)^(3^81) = 3^S
[3^(3^4)]^(3^81) = 3^S......how it is proceeded to the next step
[3^(3^85)] = 3^S
Since bases are same, so exponents will also be equal.
Hence, S = [spoiler]3^85[/spoiler]
Image
Top
Junior | Next Rank: 30 Posts
Posts: 24
Joined: Sun Aug 21, 2011 8:41 pm
Thanked: 5 times

by naveenchandra kv » Thu Dec 15, 2011 1:21 am
R = 3^81
(3^81)^(3^81) = 3^S (Split the 81 in the first term into 3^4)
[3^(3^4)]^(3^81) = 3^S......(Please note that a^m^n=a^mn)
Therefore, add 3^4 with 3^81 which becomes 3^85
SO we have 3 raise to 3^85 on LHS and 3^S on RHS
SO S becomes, 3^85.
Top
Post new topic Post Reply
• Page 1 of 1