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

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

If \(2^{4x}=3,600\), what is the value of \((2^{(1-x)})^2\)?

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Moderator
Posts: 2554
Joined: Sun Oct 15, 2017 1:50 pmFollowed by: 6 members
by BTGmoderatorLU » Fri Mar 01, 2019 3:13 pm

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty—

Source: Official Guide

If \(2^{4x}=3,600\), what is the value of \((2^{(1-x)})^2\)?

A. \(-\frac{1}{15}\)
B. \(\frac{1}{15}\)
C. \(\frac{3}{10}\)
D. \(-\frac{3}{10}\)
E. \(1\)

The OA is B
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2623
Joined: Mon Jun 02, 2008 3:17 amFollowed by: 355 members
Location: Montreal
Thanked: 1090 times
GMAT Score:780

by Ian Stewart » Sat Mar 02, 2019 4:07 am
2^(4x) = 3600, so (2^2)^2x = 3600, and 4^(2x) = 3600. Taking square roots, 4^x = 60.

We want to find the value of (2^(1-x))^2 = (2^2)^(1-x) = 4^(1-x) = 4^1 * 4^(-x)

Since 4^x = 60, 4^(-x) is equal to 1/60, so 4^1 * 4^(-x) = 4 * (1/60) = 4/60 = 1/15
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2623
Joined: Mon Jun 02, 2008 3:17 amFollowed by: 355 members
Location: Montreal
Thanked: 1090 times
GMAT Score:780

by Ian Stewart » Sat Mar 02, 2019 4:10 am
Alternatively:

2^(4x) = 3600
2^(2x) = 60
2^x = √60

So

(2^(1-x))^2 = (2 / 2^x)^2 = (2/√60)^2 = 4/60 = 1/15
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com

ianstewartgmat.com
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pmFollowed by: 1906 members
Location: New York, NY
Thanked: 13060 times
GMAT Score:790

by GMATGuruNY » Sat Mar 02, 2019 4:30 am
BTGmoderatorLU wrote:Source: Official Guide

If \(2^{4x}=3,600\), what is the value of \((2^{(1-x)})^2\)?

A. \(-\frac{1}{15}\)
B. \(\frac{1}{15}\)
C. \(\frac{3}{10}\)
D. \(-\frac{3}{10}\)
E. \(1\)
\((2^{(1-x)})^2\) = \(2^{2-2x}\) = \(2^2/2^{2x}\) = \(4/2^{2x}\)

We need to know the value of \(2^{2x}\):
\(2^{4x}=3,600\)
\((2^{2x})^2=3,600\)
\(2^{2x}= 60\)

Substituting \(2^{2x}= 60\) into \(4/2^{2x}\), we get:
4/60 = 1/15

The correct answer is B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8154
Joined: Sat Apr 25, 2015 10:56 amFollowed by: 29 members
Location: Los Angeles, CA
Thanked: 43 times

by Scott@TargetTestPrep » Wed Mar 06, 2019 6:55 pm
BTGmoderatorLU wrote:Source: Official Guide

If \(2^{4x}=3,600\), what is the value of \((2^{(1-x)})^2\)?

A. \(-\frac{1}{15}\)
B. \(\frac{1}{15}\)
C. \(\frac{3}{10}\)
D. \(-\frac{3}{10}\)
E. \(1\)

The OA is B
Let's first simplify the expression we want to evaluate. We see that [2^(1-x)]^2 can be simplified as (2 * 2^(-x))^2 = 2^2 * 2^(-2x) = (2^2)/(2^(2x))

Thus, if we can determine 2^2x, then we have an answer.

Taking the square root of both sides of the given equation, which is 2^(4x) = 3600, we have 2^(2x) = 60; thus:

(2^2)/(2^(2x)) = 4/60 = 1/15

Answer: B

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1