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 →

Adding Exponents - tough gmat problem

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 101
Joined: Tue Apr 07, 2009 12:30 am
Thanked: 2 times
GMAT Score:750

by Svedankae » Sun Sep 13, 2009 9:36 am
...there is no remainder, or am i mistaken?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 6
Joined: Sun Sep 13, 2009 12:31 pm

by FinanceBioE » Sun Sep 13, 2009 12:37 pm
is this 3^(4n + 2 + 1) or 3^(4n) + 2 + 1
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 7
Joined: Sat Jan 17, 2009 5:33 am

by tg » Sun Sep 13, 2009 2:19 pm
FinanceBioE: To clarify, the question is:

3^(4n + 2) + 1 divided by 10.

Svedankae, you are correct. The answer is 0, there is no remainder. Could you please show me how you came to this answer?

Thank you very much.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Mon Sep 14, 2009 11:54 am

by ichip_tpt » Mon Sep 14, 2009 11:59 am
3^(4n+2) can be written as 3^4n * 3^2 = 9 * 3^4n.

For all n = 0, 1, 2, 3 ..., the units digit of 3^4n is 1.

n=0; 3^0 -> units digit is 1
n=1; 3^4 -> units digit is 1
n=2; 3^8 -> units digit is 1
...

=> the units digit of 9 * 3^4n is 9, to which when 1 is added the units digits would be 0, which is clearly divisible by 10 and hence the remainder is 0.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 7
Joined: Sat Jan 17, 2009 5:33 am

by tg » Mon Sep 14, 2009 8:47 pm
Thank you ichip_tpt. This explanation is perfect. :)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1