Last visit was: 25 Apr 2026, 11:30 It is currently 25 Apr 2026, 11:30
Home
Messages
Tests
Schools
Events
Close
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
Your Progress

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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
Sub 505 (Easy)|   Exponents|      
User avatar
MathRevolution
User avatar
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Last visit: 27 Sep 2022
Posts: 10,063
Own Kudos:
20,004
 [1]
Given Kudos: 4
GMAT 1: 760 Q51 V42
GPA: 3.82
Expert
Expert reply
GMAT 1: 760 Q51 V42
Posts: 10,063
Kudos: 20,004
 [1]
If 8x=2^y, what is the value of x, in terms of y? 06 Oct 2017, 02:44
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

5% (low)

Question Stats:

95% (00:48) correct 5% (01:38) wrong based on 143 sessions

History

Date
Time
Result
Not Attempted Yet
[GMAT math practice question]

If \(8x=2^y\), what is the value of x, in terms of y?

A. \(x=2^{3y-2}\)
B. \(x=4y\)
C. \(x=4^{y-2}\)
D. \(x=2^{y-3}\)
E. \(x=2y\)
ShowHide Answer
Official Answer
D
User avatar
NandishSS
User avatar
Joined: 06 Jan 2015
Last visit: 28 Jan 2021
Posts: 701
Own Kudos:
1,787
Given Kudos: 579
Location: India
Concentration: Operations, Finance
GPA: 3.35
WE:Information Technology (Computer Software)
Posts: 701
Kudos: 1,787
If 8x=2^y, what is the value of x, in terms of y? 06 Oct 2017, 04:26
Kudos
Add Kudos
Bookmarks
Bookmark this Post
MathRevolution
[GMAT math practice question]

If \(8x=2^y\), what is the value of x, in terms of y?

A. \(x=2^{3y-2}\)
B. \(x=4y\)
C. \(x=4^{y-2}\)
D. \(x=2^{y-3}\)
E. \(x=2y\)
Show more

\(8x=2^y\) ==> \(2^3x=2^y\) ==> \(x=2^y/(2^3)\) ==>\(x=2^{y-3}\)

Ans - D
User avatar
MathRevolution
User avatar
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Last visit: 27 Sep 2022
Posts: 10,063
Own Kudos:
20,004
Given Kudos: 4
GMAT 1: 760 Q51 V42
GPA: 3.82
Expert
Expert reply
GMAT 1: 760 Q51 V42
Posts: 10,063
Kudos: 20,004
If 8x=2^y, what is the value of x, in terms of y? 08 Oct 2017, 18:05
Kudos
Add Kudos
Bookmarks
Bookmark this Post
=>
\(8x = 2^y ⬄ 2^3x = 2^y ⬄ x = 2^{y-3}\)

Answer : D
User avatar
BrentGMATPrepNow
User avatar
Major Poster
Joined: 12 Sep 2015
Last visit: 31 Oct 2025
Posts: 6,733
Own Kudos:
36,465
Given Kudos: 799
Location: Canada
Expert
Expert reply
Posts: 6,733
Kudos: 36,465
If 8x=2^y, what is the value of x, in terms of y? 17 Jul 2018, 08:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
MathRevolution
[GMAT math practice question]

If \(8x=2^y\), what is the value of x, in terms of y?

A. \(x=2^{3y-2}\)
B. \(x=4y\)
C. \(x=4^{y-2}\)
D. \(x=2^{y-3}\)
E. \(x=2y\)
Show more

Another approach is to find some values of x and y that satisfy the given equation 8x = 2^y
One solution that works is x = 1 and y = 3, since 8(1) = 2^3
Now take each answer choice and replace x and y with 1 and 3 respectively and see which one yields a true equation:

A. 1 = 2^[3(3) - 2] Not true. ELIMINATE
B. 1 = 4(3) Not true. ELIMINATE
C. 1 = 4^(3 - 2) Not true. ELIMINATE
D. 1 = 2^(3 - 3) True. KEEP!
E. 1 = 2(3) Not true. ELIMINATE

Answer: D

Cheers,
Brent
User avatar
ScottTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 14 Oct 2015
Last visit: 25 Apr 2026
Posts: 22,286
Own Kudos:
26,537
Given Kudos: 302
Status:Founder & CEO
Affiliations: Target Test Prep
Location: United States (CA)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 22,286
Kudos: 26,537
If 8x=2^y, what is the value of x, in terms of y? 19 Jul 2018, 16:57
Kudos
Add Kudos
Bookmarks
Bookmark this Post
MathRevolution
[GMAT math practice question]

If \(8x=2^y\), what is the value of x, in terms of y?

A. \(x=2^{3y-2}\)
B. \(x=4y\)
C. \(x=4^{y-2}\)
D. \(x=2^{y-3}\)
E. \(x=2y\)
Show more

Simplifying, we have:

2^3 * x = 2^y

x = 2^y / 2^3

x = 2^(y - 3)

Answer: D
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,985
Own Kudos:
1,118
Posts: 38,985
Kudos: 1,118
If 8x=2^y, what is the value of x, in terms of y? 12 Nov 2025, 04:45
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.
Moderators:
Bunuel
Math Expert
109829 posts
Krunaal
Tuck School Moderator
852 posts