Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 563 reviewsTarget Test Prep

confused

Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 28
Joined: Mon Oct 21, 2013 12:52 am
by sgr21 » Mon Apr 14, 2014 1:41 am
What is the unit's digit of 7^{75}+6?

(A) 1
(B) 3
(C) 5
(D) 7
(E) 9

the answer i get is 1 bt some of my friends got their answer as 9

helppp plzzzz
Top
Join the discussion
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 44
Joined: Fri Feb 14, 2014 2:13 am
Thanked: 12 times

by Tushar14 » Mon Apr 14, 2014 2:06 am
As 75=4*18+3 then the last digit of 7^{75} is the same as the last digit of 7^3, which is 3. Units digit of 7^{75} + 6 will be: 3 plus 6 = 9.
Top
Join the discussion

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10391
Joined: Sun Jun 23, 2013 6:38 pmFollowed by: 511 members
Location: Palo Alto, CA
Thanked: 2867 times
GMAT Score:800

by [email protected] » Mon Apr 14, 2014 11:18 am
Hi sgr21,

The GMAT doesn't expect you to calculate the value of 7^75; instead, let's try to figure out the pattern behind this math….

The question asks for the UNITS DIGIT, so we'll focus on that…

7^1 = 7
7^2 = 49
7^3 = 343
7^4 = ends in a 1

7^5 = ends in a 7
7^6 = ends in a 9
etc.

The pattern is 7931 7931 7931 etc.

So the units digit will follow this repeating pattern of 4 digits…

75/4 = 18r3

Thus, the 75th number will be the "third number" in the pattern…a 3

The question asks us to ADD 6 to this number though….

3+6 = 9

Final Answer: E

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image
Top
Join the discussion