GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 10 Dec 2018, 01:03

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 in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • Free lesson on number properties

     December 10, 2018

     December 10, 2018

     10:00 PM PST

     11:00 PM PST

    Practice the one most important Quant section - Integer properties, and rapidly improve your skills.
  • Free GMAT Prep Hour

     December 11, 2018

     December 11, 2018

     09:00 PM EST

     10:00 PM EST

    Strategies and techniques for approaching featured GMAT topics. December 11 at 9 PM EST.

The digits 0 to 9 are used to form three digit codes; however, there a

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51055
The digits 0 to 9 are used to form three digit codes; however, there a  [#permalink]

Show Tags

New post 02 Oct 2018, 01:12
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

78% (01:45) correct 22% (02:22) wrong based on 49 sessions

HideShow timer Statistics

The digits 0 to 9 are used to form three digit codes; however, there are a few conditions to be followed: the first digit cannot be 0 or 9, the second digit must be 0 or 9, and the second and third digits cannot both be ‘9’ in the same code. If the digits may be repeated in the same code, how many different codes are possible?

(A) 152
(B) 156
(C) 160
(D) 729
(E) 1000

_________________

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

Director
Director
User avatar
G
Joined: 20 Feb 2015
Posts: 796
Concentration: Strategy, General Management
Premium Member
Re: The digits 0 to 9 are used to form three digit codes; however, there a  [#permalink]

Show Tags

New post 02 Oct 2018, 06:09
Bunuel wrote:
The digits 0 to 9 are used to form three digit codes; however, there are a few conditions to be followed: the first digit cannot be 0 or 9, the second digit must be 0 or 9, and the second and third digits cannot both be ‘9’ in the same code. If the digits may be repeated in the same code, how many different codes are possible?

(A) 152
(B) 156
(C) 160
(D) 729
(E) 1000


Case 1
take 0 as the second digit

no of ways we can select the first digit = 10-2(cannot be 0 or 9) = 8 ways
no of ways we can select second digit = 1 way ( 0 )
no of ways we can select the third digit = 10 ways
total = 8*1*10 = 80 ways

case 2
when the second digit is 9 , we have 8*1*9 = 72 ways
total 80+72 = 152 ways
A
GMAT Club Bot
Re: The digits 0 to 9 are used to form three digit codes; however, there a &nbs [#permalink] 02 Oct 2018, 06:09
Display posts from previous: Sort by

The digits 0 to 9 are used to form three digit codes; however, there a

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.