It is currently 20 Apr 2018, 09:19

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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A 9-character numeric passcode is constructed at random. If the last n

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 44586
A 9-character numeric passcode is constructed at random. If the last n [#permalink]

Show Tags

New post 13 Apr 2018, 03:29
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (01:57) correct 0% (00:00) wrong based on 34 sessions

HideShow timer Statistics

A 9-character numeric passcode is constructed at random. If the last number cannot be prime and the first digit cannot be 0, 1, or 7, how many different codes can be constructed?

A. 210,000,000
B. 300,000,000
C. 360,000,000
D. 420,000,000
E. 560,000,000

The OA will be automatically revealed on Friday 20th of April 2018 03:29:21 AM Pacific Time Zone
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
B
Joined: 30 May 2017
Posts: 42
Location: United States
Schools: HBS '21
GMAT 1: 690 Q50 V32
GRE 1: 332 Q164 V168
GPA: 3.57
A 9-character numeric passcode is constructed at random. If the last n [#permalink]

Show Tags

New post 13 Apr 2018, 05:21
1
This post was
BOOKMARKED
Bunuel wrote:
A 9-character numeric passcode is constructed at random. If the last number cannot be prime and the first digit cannot be 0, 1, or 7, how many different codes can be constructed?

A. 210,000,000
B. 300,000,000
C. 360,000,000
D. 420,000,000
E. 560,000,000



The first digit excludes [0, 1 and 7] , therefore 7 possible values.
The last digit excludes [2, 3, 5 and 7] therefore 6 possible values
The second to eight digits (7 digits) can have all 10 values

Therefore different codes that can be constructed is 7*10*10*10*10*10*10*10*6 = 7*6*(10^7) = 420,000,000

Hence option D = 420,000,000 is the answer.

Give me +1 Kudos if you like the explanation. Thanks.
_________________

Give me +1 Kudos if you like the explanation. Thanks a lot!!!

Expert Post
Target Test Prep Representative
User avatar
G
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 2447
Location: United States (CA)
Re: A 9-character numeric passcode is constructed at random. If the last n [#permalink]

Show Tags

New post 16 Apr 2018, 17:05
Bunuel wrote:
A 9-character numeric passcode is constructed at random. If the last number cannot be prime and the first digit cannot be 0, 1, or 7, how many different codes can be constructed?

A. 210,000,000
B. 300,000,000
C. 360,000,000
D. 420,000,000
E. 560,000,000


We have 7 options for the first digit. We have 10 options for each of the second to eighth digits (any digit 0 through 9, inclusive), and 6 options for the last digit (because the final digit cannot be 2, 3, 5, or 7).

So we have a total of 7 x 10^7 x 6 = 42 x 10^7 = 420,000,000 codes.

Answer: D
_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Re: A 9-character numeric passcode is constructed at random. If the last n   [#permalink] 16 Apr 2018, 17:05
Display posts from previous: Sort by

A 9-character numeric passcode is constructed at random. If the last n

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.