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 →

GMAT prep Exponents

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
User avatar
Community Manager
Posts: 991
Joined: Thu Sep 23, 2010 6:19 amFollowed by: 24 members
Location: Bangalore, India
Thanked: 146 times

by shovan85 » Thu Oct 21, 2010 2:39 am
The Q is (1/5)^m (1/4)^18= 1/2(10)^35

=> 5 ^ -m * (2 ^ -2)^18 = (2 ^ -1 )* (10 ^ -35)

=> (5^-m) * (2^-36) = (2 ^ -1 )* (2 ^ -35) * (5 ^ -35 )

=> 5^-m = [ (2 ^ -36) * (5 ^ -35 )] / (2^-36) = (5 ^ -35 )

=> 5^-m = (5 ^ -35 )

=> m = 35
If the problem is Easy Respect it, if the problem is tough Attack it
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
GMAT Instructor
Posts: 905
Joined: Sun Sep 12, 2010 1:38 amFollowed by: 123 members
Thanked: 378 times
GMAT Score:760

by Geva@EconomistGMAT » Thu Oct 21, 2010 5:16 am
taneja.niks wrote:If (1/5)m(1/4)18 = 1/2(10)35, m?

on simplifying i get

(5^-35)(2^-35) = (2^35)(5^35)

how to proceed further???

Plz explain
ans m=35
You lost the m somewhere. Doesn't matter.

Shovan gave a possible explanation - I'd just like to point out the overall motive of solving exponential equations.
Whenever you have variables in the exponents, the solution is to rewrite the powers so that the bases are the same on both sides of the equation.
In the example above, you want to get everything on both sides to (5^something) * (2 ^something)

Once you have that, you can ignore the bases and equate the exponents. If 5^m*2^x equals 5*35*2^70, then
m=35
and
x=70.

Note that in the question above, you don't even need to mess around with the 2s and 4s, as only the 5s have variables in the exponents. Thus, the problem can be solved by breaking down 10 into 2*5, isolating (1/5)35 to have the same base as (1/5)^m on the left side, then, since the bases are the same, ignore the bases of 1/5 and equate the exponents: m=35.
Geva
Senior Instructor
Master GMAT
1-888-780-GMAT
https://www.mastergmat.com
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 155
Joined: Wed Sep 22, 2010 3:54 am
Thanked: 6 times

by pzazz12 » Fri Oct 22, 2010 4:02 am
shovan85 wrote:The Q is (1/5)^m (1/4)^18= 1/2(10)^35

=> 5 ^ -m * (2 ^ -2)^18 = (2 ^ -1 )* (10 ^ -35)

=> (5^-m) * (2^-36) = (2 ^ -1 )* (2 ^ -35) * (5 ^ -35 )

=> 5^-m = [ (2 ^ -36) * (5 ^ -35 )] / (2^-36) = (5 ^ -35 )

=> 5^-m = (5 ^ -35 )

=> m = 35
simply great yar :) ....thank u very much...
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1