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
GMATLiveTeach Starts Oct 17
Chris Peckover, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Chris Peckover, 100th-Percentile GMAT Scorer

Oct 17 · Chris Peckover
Sat · 11:00 AM to 2:00 PM ET
Oct 20 · Chris Peckover
Tue, Thu · 8:00 to 10:00 PM ET
Oct 25 · Josh Braslow
Sun · 1:00 to 4:00 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
EALiveTeachOnDemand 5 seats left Start anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

165+ EA score guarantee
$05-day trial no automatic billing
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 Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget 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.

Combination

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 66
Joined: Mon Jun 14, 2010 4:46 am
Thanked: 3 times
by JeetGulia » Tue Sep 14, 2010 3:19 am
A certain stock exchange designates each stock with one, two or three letter codes, where each letter is selected from the 26 letters. If the letters may be repeated and if the same letters used in a different order is a different code, how many different stocks codes are possibile.

a) 2,951
b) 8125
c) 15,600
d) 16,302
e) 18,278

ans E

Please help
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: 1179
Joined: Sun Apr 11, 2010 9:07 pmFollowed by: 88 members
Location: Milpitas, CA
Thanked: 447 times

by Rahul@gurome » Tue Sep 14, 2010 3:53 am
One letter code can be designated in 26 ways.
Two letter codes can be designated in 26^2 ways.
Three letter codes can be designated in 26^3 ways.
Therefore, number of stock codes possible = 26 + 26^2 + 26^3 = 18,278

The correct answer is [spoiler](E)[/spoiler].
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 77
Joined: Mon Jul 12, 2010 12:14 am
Location: India
GMAT Score:710

by rb90 » Mon Sep 27, 2010 5:03 am
But why dont we have to use permutation also in this sum? Since the sum hints at arrangement ..please help,im confused.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 120
Joined: Thu Sep 02, 2010 8:56 am
Location: India
Thanked: 7 times
GMAT Score:730

by euro » Mon Sep 27, 2010 8:18 am
rb90 wrote:But why dont we have to use permutation also in this sum? Since the sum hints at arrangement ..please help,im confused.
We don't use permutation {nPr formula} because no restriction is imposed here...
"the letters may be repeated and if the same letters used in a different order is a different code"

In case of two letter codes, the first position can be filled by any of the 26 alphabets and the second position can also be filled by any of the 26 alphabets. The two positions can be filled in 26 x 26 = 26^2 ways.

Similarly, for three-letter codes, the three positions can be filled in 26^3 ways (since repetition is allowed).

If repetition is allowed, for 'n' distinct objects taken 'r' at a time, the number of arrangements possible is n^r.

:)
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 12
Joined: Sat May 22, 2010 11:36 pm
Thanked: 3 times

by msbinu » Mon Sep 27, 2010 8:19 am
rb90 wrote:But why dont we have to use permutation also in this sum? Since the sum hints at arrangement ..please help,im confused.
Hi ,
We can use permutation also to solve this.

1 letter code can be selected from 26 letters using 26P1 ways = 26!/25! = 26
2 letter code could be selected in 26P1 * 26 P 1 ways = 26 * 26 = 676
3 letter code could be selected in 26p1 * 26P1 * 26 P1 ways = 26 * 26 * 26 = 17576

Hence total = 18278 .
:)
Hope this helps
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1