Last visit was: 12 Dec 2024, 01:37 It is currently 12 Dec 2024, 01:37
Home
GMAT
Messages
Tests
Schools
Reviews
Social
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
605-655 Level|   Algebra|   Exponents|      
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 11 Dec 2024
Posts: 97,827
Own Kudos:
685,204
 [18]
Given Kudos: 88,254
Products:
GMAT Club Tests Forum Quiz
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 97,827
Kudos: 685,204
 [18]
If a, b, c, d, and e are positive integers such that 19 Jun 2015, 02:07
Kudos
Add Kudos
18
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:

45% (medium)

Question Stats:

68% (01:57) correct 32% (02:06) wrong based on 606 sessions

History

Date
Time
Result
Not Attempted Yet
If a, b, c, d, and e are positive integers such that \(\frac{a*10^d}{b*10^e}=c*10^4\) is bc/a an integer?

(1) d – e ≥ 4
(2) d – e > 4


Kudos for a correct solution.
ShowHide Answer
Official Answer
D
Most Helpful Reply
User avatar
ManojReddy
User avatar
Joined: 28 Jan 2013
Last visit: 24 Sep 2024
Posts: 31
Own Kudos:
124
 [7]
Given Kudos: 32
Location: United States
Concentration: General Management, International Business
Schools: NUS '17 Tepper '17 ISB '17
GPA: 3.1
WE:Information Technology (Consulting)
Schools: NUS '17 Tepper '17 ISB '17
Posts: 31
Kudos: 124
 [7]
If a, b, c, d, and e are positive integers such that 19 Jun 2015, 02:24
5
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
If a, b, c, d, and e are positive integers such that \(\frac{a∗10^d}{b∗10^e}\)=\(c∗10^4\) is bc/a an integer?

\(\frac{a∗10^d}{b∗10^e}\)=\(c∗10^4\)
bc/a = \(\frac{10^d}{10^e*10^4}\)

bc/a = \(10^{d-e-4}\)

for bc/a to be integer, {d-e-4} should be an integer greater than 0

(1) d – e ≥ 4

{d-e} can take any value greater than or equal to 4
so d-e-4 will be ≥ 0

Ex: d-e =4 then bc/a = 10^0 = 1
d-e =5 then bc/a = 10^1 = 10

so bc/a is integer

Sufficient.

(2) d – e > 4

{d-e} can take any value greater than 4
so d-e-4 will be ≥ 1

so bc/a is integer
Sufficient

Ans: D
General Discussion
avatar
shriramvelamuri
avatar
Joined: 27 Dec 2013
Last visit: 29 Jun 2016
Posts: 163
Own Kudos:
130
 [1]
Given Kudos: 113
Posts: 163
Kudos: 130
 [1]
If a, b, c, d, and e are positive integers such that 19 Jun 2015, 02:49
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Yes It has to be D.

10^0 =1 an Integer

10^ any number= integer.


Bunuel
If a, b, c, d, and e are positive integers such that \(\frac{a*10^d}{b*10^e}=c*10^4\) is bc/a an integer?

(1) d – e ≥ 4
(2) d – e > 4


Kudos for a correct solution.
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 11 Dec 2024
Posts: 97,827
Own Kudos:
685,204
 [4]
Given Kudos: 88,254
Products:
GMAT Club Tests Forum Quiz
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 97,827
Kudos: 685,204
 [4]
If a, b, c, d, and e are positive integers such that 22 Jun 2015, 06:09
2
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
Bunuel
If a, b, c, d, and e are positive integers such that \(\frac{a*10^d}{b*10^e}=c*10^4\) is bc/a an integer?

(1) d – e ≥ 4
(2) d – e > 4


Kudos for a correct solution.

MANHATTAN GMAT OFFICIAL SOLUTION:
Attachment:
2015-06-22_1708.png
2015-06-22_1708.png [ 84.26 KiB | Viewed 10230 times ]
avatar
OptimusPrepJanielle
avatar
Joined: 06 Nov 2014
Last visit: 08 Sep 2017
Posts: 1,786
Own Kudos:
1,411
Given Kudos: 23
Expert reply
Posts: 1,786
Kudos: 1,411
If a, b, c, d, and e are positive integers such that 22 Jun 2015, 13:35
Kudos
Add Kudos
Bookmarks
Bookmark this Post
If a, b, c, d, and e are positive integers such that (a∗10^d)/(b∗10^e)=c∗10^4 is bc/a an integer?

(1) d – e ≥ 4 sufficient
(2) d – e > 4 sufficient
Attachments

Untitled.jpg
Untitled.jpg [ 30.51 KiB | Viewed 10120 times ]

User avatar
iliavko
User avatar
Joined: 08 Dec 2015
Last visit: 28 Apr 2019
Posts: 257
Own Kudos:
125
 [2]
Given Kudos: 36
GMAT 1: 600 Q44 V27
Products:
My Reviews
GMAT 1: 600 Q44 V27
Posts: 257
Kudos: 125
 [2]
If a, b, c, d, and e are positive integers such that 25 Jun 2016, 02:10
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Strange question, why do even need the statements to answer?

It says that A/B=C and I don't see how the powers of 10 are relevant. We are told from the stem that a,b,c are positive integers, so A is a multiple of B and B is a multiple of C (A is a multiple of C) so obviously if we "reverse" the operation and multiple C*B we get A and BC/A will yield 1. Given the stem, there is no way A/B=C is not an integer! Even if we consider that C could be a fraction, but then again we are told that c is *\(10^4\) so it's a not a fraction, it's an integer.

Then the statements say that d-e = 4 or 4+?.. Well it's already in the question stem, it says there that d-e is 4 (same base 10 we subtract d-e to get base 10 power 4). No new information.

So what is being asked?...
avatar
hsbinfy
avatar
Joined: 02 Mar 2012
Last visit: 13 Nov 2017
Posts: 196
Own Kudos:
307
Given Kudos: 4
Schools: Schulich '16
Schools: Schulich '16
Posts: 196
Kudos: 307
If a, b, c, d, and e are positive integers such that 25 Jun 2016, 04:52
Kudos
Add Kudos
Bookmarks
Bookmark this Post
D

strange choices but both say same leaving =4

1)if you reduce the expression it will come as bc/a =10^d-e-4.So if d-e>=4 the output will always be an integer.

2) also says the same d-e>4 always an intergerv
avatar
Ashish632
avatar
Joined: 13 May 2020
Last visit: 27 Mar 2022
Posts: 16
Own Kudos:
9
Given Kudos: 39
Posts: 16
Kudos: 9
If a, b, c, d, and e are positive integers such that 22 Jul 2020, 21:25
Kudos
Add Kudos
Bookmarks
Bookmark this Post
well a quick doubt here , here it says d-3 greater than or equal to 4 , well lets say d-3 is 4.5 so it leads to the equation being 10^0.5 , which may not be an integer isnt it ...

Can someone clarify ????
avatar
Ashish632
avatar
Joined: 13 May 2020
Last visit: 27 Mar 2022
Posts: 16
Own Kudos:
9
Given Kudos: 39
Posts: 16
Kudos: 9
If a, b, c, d, and e are positive integers such that 22 Jul 2020, 21:26
Kudos
Add Kudos
Bookmarks
Bookmark this Post
oh sorry , my bad , i just realised , that its given that all are integers , well lets just say that its not given that they are integers , in that case , is my assumption correct , will the answer be E then ?
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 35,789
Own Kudos:
929
Posts: 35,789
Kudos: 929
If a, b, c, d, and e are positive integers such that 10 Aug 2022, 09:17
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Moderator:
Bunuel
Math Expert
97827 posts