Last visit was: 19 Nov 2025, 12:13 It is currently 19 Nov 2025, 12:13
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
User avatar
EgmatQuantExpert
User avatar
e-GMAT Representative
Joined: 04 Jan 2015
Last visit: 02 Apr 2024
Posts: 3,663
Own Kudos:
20,166
 [2]
Given Kudos: 165
Expert
Expert reply
Posts: 3,663
Kudos: 20,166
 [2]
An unfortunate thief was caught while trying to decode the 3-digit num 29 May 2018, 01:51
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

25% (medium)

Question Stats:

70% (01:06) correct 30% (01:29) wrong based on 310 sessions

History

Date
Time
Result
Not Attempted Yet
An unfortunate thief was caught while trying to decode the 3-digit numerical code of a lock. The Police caught him while he was making the second-last possible unique attempt. How many attempts did the thief make in total?

A. 5
B. 26
C. 719
D. 999
E. 1000


To solve question 4: P&C Practice Question 4

Related Articles:

Article-1: Learn when to “Add” and “Multiply” in Permutation & Combination questions
Article-2: Fool-proof method to Differentiate between Permutation & Combination Questions
Article-3: 3 deadly mistakes you must avoid in Permutation & Combination

All Articles: Must Read Articles and Practice Questions to score Q51 !!!!
ShowHide Answer
Official Answer
D
User avatar
pushpitkc
User avatar
Joined: 26 Feb 2016
Last visit: 19 Feb 2025
Posts: 2,802
Own Kudos:
6,063
Given Kudos: 47
Location: India
GPA: 3.12
Posts: 2,802
Kudos: 6,063
An unfortunate thief was caught while trying to decode the 3-digit num 29 May 2018, 05:40
Kudos
Add Kudos
Bookmarks
Bookmark this Post
EgmatQuantExpert
An unfortunate thief was caught while trying to decode the 3-digit numerical code of a lock. The Police caught him while he was making the second-last possible unique attempt. How many attempts did the thief make in total?

A. 5
B. 26
C. 719
D. 999
E. 1000
Show more

We are talking about the 3-digit numerical code. There are 10^3 or 1000 possibilities.
Since the thief is making his second-last possible unique attempt, he would be making
his 1000-1 = 999 attempt.

Therefore, the thief will be making his 999th attempt(Option D)
User avatar
EgmatQuantExpert
User avatar
e-GMAT Representative
Joined: 04 Jan 2015
Last visit: 02 Apr 2024
Posts: 3,663
Own Kudos:
20,166
 [1]
Given Kudos: 165
Expert
Expert reply
Posts: 3,663
Kudos: 20,166
 [1]
An unfortunate thief was caught while trying to decode the 3-digit num 31 May 2018, 01:53
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post

Solution



Given:
    • The thief was trying to decode a 3-digit numerical code of a lock
    • He was caught while making the second-last possible event

To find:
    • In total, how many attempts did the thief make

Approach and Working:
    • As it is a 3-digit numerical code, every place in the code can be filled by 10 possible digits
    • Therefore, total number of possible codes = 10 * 10 * 10 = 1000
However, among all the 1000 codes, only 1 is correct
    • Therefore, the maximum number of unsuccessful attempts = second-last possible unique attempts = 1000 – 1 = 999

Hence, the correct answer is option D.

Answer: D
User avatar
altairahmad
User avatar
Joined: 27 Mar 2017
Last visit: 29 Jul 2021
Posts: 263
Own Kudos:
87
Given Kudos: 406
Location: Saudi Arabia
Schools: Tepper '23 (A$) LBS '23 (I) INSEAD Jan 22 intake (A)
GMAT 1: 700 Q47 V39
GPA: 3.36
Products:
My Reviews
Schools: Tepper '23 (A$) LBS '23 (I) INSEAD Jan 22 intake (A)
GMAT 1: 700 Q47 V39
Posts: 263
Kudos: 87
An unfortunate thief was caught while trying to decode the 3-digit num 09 Aug 2019, 22:53
Kudos
Add Kudos
Bookmarks
Bookmark this Post
EgmatQuantExpert

Solution



Given:
    • The thief was trying to decode a 3-digit numerical code of a lock
    • He was caught while making the second-last possible event

To find:
    • In total, how many attempts did the thief make

Approach and Working:
    • As it is a 3-digit numerical code, every place in the code can be filled by 10 possible digits
    • Therefore, total number of possible codes = 10 * 10 * 10 = 1000
However, among all the 1000 codes, only 1 is correct
    • Therefore, the maximum number of unsuccessful attempts = second-last possible unique attempts = 1000 – 1 = 999

Hence, the correct answer is option D.

Answer: D
Show more

Hi,

I have a questions regarding this. When we say 10x10x10 will this method count e.g a combination of 322 as one of two possible identical choices ? I mean will it consider the two 2s as different or as same ? My guess is that since this is a permutation based approach it will count the two 322s as different. Similarly the result should contain three combinations of 333s. Is this true ?

Will appreciate a response on this.
User avatar
ScottTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 14 Oct 2015
Last visit: 19 Nov 2025
Posts: 21,716
Own Kudos:
26,996
Given Kudos: 300
Status:Founder & CEO
Affiliations: Target Test Prep
Location: United States (CA)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 21,716
Kudos: 26,996
An unfortunate thief was caught while trying to decode the 3-digit num 12 Aug 2020, 14:24
Kudos
Add Kudos
Bookmarks
Bookmark this Post
EgmatQuantExpert
An unfortunate thief was caught while trying to decode the 3-digit numerical code of a lock. The Police caught him while he was making the second-last possible unique attempt. How many attempts did the thief make in total?

A. 5
B. 26
C. 719
D. 999
E. 1000


Show more
Solution:

The second-last attempt is the same thing as the next-to-last attempt. Since there are 10 x 10 x 10 = 1000 codes possible, including his second-last possible attempt, the thief has made a total of 999 attempts.

Answer: D
Moderators:
Bunuel
Math Expert
105390 posts
Krunaal
Tuck School Moderator
805 posts