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

Redeem

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.

★★★★★5.0559 reviews
Vote for Target Test Prep, Newsweek Readers’ Choice Awards 2026
NEWSWEEK READERS’ CHOICE 2026

BIG NEWS! Target Test Prep has been nominated, and they’d love your vote!

TTP has worked incredibly hard to build the best test prep experience possible, and winning Newsweek’s 2026 Readers’ Choice Award for Best Test Prep would mean a lot to them. If TTP has helped you, they’d be incredibly grateful for your vote. You can vote once each day through September 9.

Vote for TTP
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
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
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start 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 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

tricky digits problem: units digit of a three digit number

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 158
Joined: Mon Nov 02, 2009 5:49 pmFollowed by: 3 members
Thanked: 2 times
by tonebeeze » Tue Apr 26, 2011 3:23 pm
Confused. Please help.

If the units digit of the three-digit positive integer k is nonzero, what is the tens digit of k?

1. The tens digit of k + 9 is 3

2. The tens digit of k + 4 is 2
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
User avatar
Legendary Member
Posts: 965
Joined: Thu Jan 28, 2010 12:52 amFollowed by: 34 members
Thanked: 156 times
GMAT Score:720

by vineeshp » Tue Apr 26, 2011 4:44 pm
1) Sufficient.
if unit's digit is non zero, then the number ends with one of 1-9.

If the tens digit of k + 9 is 3, then k+9 is between 30-38.
k is between 21-29.

Hence tens digit is 2.
(even if you take 121,221 etc, the argument still holds good.)

2) Insufficient.
k + 4 has tens digit as 2.

say k ends in 18, then k + 4 would have tens digit 2.
say k ends in 22, then k + 4 would have tens digit 2.

So we cant predict the tens digit of k.
Vineesh,
Just telling you what I know and think. I am not the expert. :)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pmFollowed by: 523 members
Location: Milpitas, CA
Thanked: 1854 times
GMAT Score:770

by Anurag@Gurome » Wed Apr 27, 2011 4:51 am
tonebeeze wrote:Confused. Please help.

If the units digit of the three-digit positive integer k is nonzero, what is the tens digit of k?

1. The tens digit of k + 9 is 3

2. The tens digit of k + 4 is 2
Let k = XYZ, so that Z is non zero.

(1) The tens digit of k + 9 is 3 implies tens digit of (XYZ + 9) = 3
The minimum digit of Z can be 1 (as it non-zero). Then XY1 + 9 implies the units digit will be 0, with a carry over of 1 to tens place. And since tens digit of k + 9 is 3, so Y = 2.
The maximum digit of Z can be 9. Then XY9 + 9 implies units digit will be 8, with a carry over of 1 to tens place. So, again Y = 2.
So, the tens digit of k is 2.
Hence, (1) is SUFFICIENT.

(2) The tens digit of k + 4 is 2 implies tens digit of (XYZ + 4) = 2
If Z = 2, then (X22 + 4) = X26, here tens digit of k = 2
If Z = 8, then (X18 + 4) = X22, here tens digit of k = 1
We don't get a definite answer.
Hence, (2) is NOT SUFFICIENT.

The correct answer is A.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
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 » Wed Apr 27, 2011 6:14 am
tonebeeze wrote:Confused. Please help.

If the units digit of the three-digit positive integer k is nonzero, what is the tens digit of k?

1. The tens digit of k + 9 is 3

2. The tens digit of k + 4 is 2
Statement 1: The tens digit of k+9 is 3.
Between 100 and 200:
k+9 could be 130 through 139.
Thus, k could be 130-9 = 121 through 139-9 = 130.
Since the units digit of k must be nonzero, k cannot be 130.
Thus, k = {121...129}.
Using this same logic, between 200 and 300:
k = {221...229}.
And so on.
In every case, the tens digit of k is 2.
Sufficient.

Statement 2: The tens digit of k + 4 is 2.
Between 100 and 200:
k+4 could be 120 through 129.
Thus, k could be 120-4 = 116 through 129-4 = 125 (excluding 120, since the units of k must be nonzero).
Thus, the tens digit of k could be 1 or 2.
Insufficient.

The correct answer is A.
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
Post new topic Post Reply
• Page 1 of 1