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

 It is currently 20 Feb 2019, 07:43

### 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

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

## Events & Promotions

###### Events & Promotions in February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• ### Free GMAT Prep Hour

February 20, 2019

February 20, 2019

08:00 PM EST

09:00 PM EST

Strategies and techniques for approaching featured GMAT topics. Wednesday, February 20th at 8 PM EST

February 21, 2019

February 21, 2019

10:00 PM PST

11:00 PM PST

Kick off your 2019 GMAT prep with a free 7-day boot camp that includes free online lessons, webinars, and a full GMAT course access. Limited for the first 99 registrants! Feb. 21st until the 27th.

# If a, b, and c are positive integers such that a is divisible by b, an

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 53020
If a, b, and c are positive integers such that a is divisible by b, an  [#permalink]

### Show Tags

13 Dec 2015, 03:47
00:00

Difficulty:

15% (low)

Question Stats:

81% (01:43) correct 19% (01:44) wrong based on 95 sessions

### HideShow timer Statistics

If a, b, and c are positive integers such that a is divisible by b, and c is divisible by a, which of the following is NOT necessarily an integer?

A. (a + c)/b
B. (c - a)/b
C. ca/b
D. (c + b)/a
E. cb/a

_________________
VP
Joined: 05 Mar 2015
Posts: 1001
Re: If a, b, and c are positive integers such that a is divisible by b, an  [#permalink]

### Show Tags

13 Dec 2015, 09:14
[quote="Bunuel"]If a, b, and c are positive integers such that a is divisible by b, and c is divisible by a, which of the following is NOT necessarily an integer?

A. (a + c)/b
B. (c - a)/b
C. ca/b
D. (c + b)/a
E. cb/a

Ans:-D

a=bx.........(1)
c=aY.........(2)

a. (A+C)/B = (bx+ay)/b = (bx+ bxy)/b =x+xy=integer
b. (c-a)/b = (ay-a)/b = a(y-1)/b = bx(y-1)/b = integer.

similarly

All options were integer except D.

d.(c+b)/a
ay+b)/a .....not integer......

Ans D
Director
Joined: 20 Feb 2015
Posts: 795
Concentration: Strategy, General Management
Re: If a, b, and c are positive integers such that a is divisible by b, an  [#permalink]

### Show Tags

13 Dec 2015, 09:28
as per the question.

let a be 15
b be 5
and c be 45

plugging in the values in answer choices only option D turns out not to be an integer.

verify the result by plugging in a=9,b=3 and c=27 or a=14, b =7 and c=35
Non-Human User
Joined: 09 Sep 2013
Posts: 9862
Re: If a, b, and c are positive integers such that a is divisible by b, an  [#permalink]

### Show Tags

04 Feb 2019, 05:33
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.
_________________
Re: If a, b, and c are positive integers such that a is divisible by b, an   [#permalink] 04 Feb 2019, 05:33
Display posts from previous: Sort by