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

It is currently 17 Jan 2019, 21:33

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 January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
  • The winning strategy for a high GRE score

     January 17, 2019

     January 17, 2019

     08:00 AM PST

     09:00 AM PST

    Learn the winning strategy for a high GRE score — what do people who reach a high score do differently? We're going to share insights, tips and strategies from data we've collected from over 50,000 students who used examPAL.
  • Free GMAT Strategy Webinar

     January 19, 2019

     January 19, 2019

     07:00 AM PST

     09:00 AM PST

    Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

In the 6-digit integer 543, 2xy, x and y are chosen from the digits 0

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

Hide Tags

 
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6811
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
In the 6-digit integer 543, 2xy, x and y are chosen from the digits 0  [#permalink]

Show Tags

New post 14 Jan 2018, 23:30
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

48% (02:53) correct 52% (02:28) wrong based on 46 sessions

HideShow timer Statistics

[GMAT math practice question]

In the 6-digit integer \(543, 2xy, x\) and \(y\) are chosen from the digits \(0, 2, 4, 6\) and \(8\). What is the probability that \(543, 2xy\) is divisible by \(8\)?

\(A. \frac{1}{5}\)
\(B. \frac{6}{25}\)
\(C. \frac{7}{25}\)
\(D. \frac{8}{25}\)
\(E. \frac{9}{25}\)

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Senior PS Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3334
Location: India
GPA: 3.12
Premium Member CAT Tests
In the 6-digit integer 543, 2xy, x and y are chosen from the digits 0  [#permalink]

Show Tags

New post 15 Jan 2018, 00:53
MathRevolution wrote:
[GMAT math practice question]

In the 6-digit integer \(543, 2xy, x\) and \(y\) are chosen from the digits \(0, 2, 4, 6\) and \(8\). What is the probability that \(543, 2xy\) is divisible by \(8\)?

\(A. \frac{1}{5}\)
\(B. \frac{6}{25}\)
\(C. \frac{7}{25}\)
\(D. \frac{8}{25}\)
\(E. \frac{9}{25}\)



In order to solve the question, we must know the rule for divisibility of 8.
The rule is as follows: If the last 3 digits are divisible by 8, the number is divisible by 8.

Since the last 3 digits are 2xy we need to find out how many of the combinations are divisible by 8.

They are 200,208,224,240,248,264,280,288(8 options)
The denominator must be the total options possible: 5*5 = 25

Therefore, the probability that \(543, 2xy\) is divisible by \(8\) is \(\frac{8}{25}\)(Option D)
_________________

You've got what it takes, but it will take everything you've got

Manager
Manager
User avatar
S
Joined: 20 Feb 2017
Posts: 88
Location: United States
Premium Member
Re: In the 6-digit integer 543, 2xy, x and y are chosen from the digits 0  [#permalink]

Show Tags

New post 15 Jan 2018, 10:07
1
MathRevolution wrote:
[GMAT math practice question]

In the 6-digit integer \(543, 2xy, x\) and \(y\) are chosen from the digits \(0, 2, 4, 6\) and \(8\). What is the probability that \(543, 2xy\) is divisible by \(8\)?

\(A. \frac{1}{5}\)
\(B. \frac{6}{25}\)
\(C. \frac{7}{25}\)
\(D. \frac{8}{25}\)
\(E. \frac{9}{25}\)


Total possible number - xy -> 5X5 = 25

In given question, we have 2xy as 200 is divisible by 8, we just need to worry about xy. (2xy = 200 + xy)

So combination with 0,2,4,6,8 divisible by 8 -> 00,08,24,40,48,64,80,88
_________________

*****************************************************************
Kudos are always welcome.

Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 6811
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
Re: In the 6-digit integer 543, 2xy, x and y are chosen from the digits 0  [#permalink]

Show Tags

New post 17 Jan 2018, 00:05
=>

An integer with three or more digits is divisible by 8 if and only if its last three digits from a number that is divisible by \(8\).

The values of \(2xy\) that are divisible by \(8\) are \(200, 208, 224, 240, 248, 264, 280\), and \(288\).
The total number of 6-digit integers of the form \(543,2xy\) is equal to the number of ways of choosing two digits from \(0, 2, 4, 6\) and \(8\), which is \(5*5 = 25.\)
Thus, the probability that \(543,2xy\)is divisible by \(8\) is \(\frac{8}{25}\)

Therefore, the answer is D.
Answer: D
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

GMAT Club Bot
Re: In the 6-digit integer 543, 2xy, x and y are chosen from the digits 0 &nbs [#permalink] 17 Jan 2018, 00:05
Display posts from previous: Sort by

In the 6-digit integer 543, 2xy, x and y are chosen from the digits 0

  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®.