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

 It is currently 21 Aug 2018, 06:53

### 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

# a, b, c, d are positive integers. When a is divided by b, the

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

### Hide Tags

Manager
Joined: 07 Jun 2017
Posts: 175
Location: India
Concentration: Technology, General Management
GMAT 1: 660 Q46 V38
GPA: 3.6
WE: Information Technology (Computer Software)
a, b, c, d are positive integers. When a is divided by b, the  [#permalink]

### Show Tags

16 Oct 2017, 03:33
3
00:00

Difficulty:

65% (hard)

Question Stats:

58% (01:47) correct 42% (01:49) wrong based on 45 sessions

### HideShow timer Statistics

a, b, c, d are positive integers. When a is divided by b, the remainder is 7. When c is divided by d, the remainder is 5. Which of
the following cannot be the value of the product b x d?

A. 48
B. 56
C. 63
D. 69
E. 140

_________________

Regards,
Naveen
email: nkmungila@gmail.com
Please press kudos if you like this post

Math Expert
Joined: 02 Aug 2009
Posts: 6559
Re: a, b, c, d are positive integers. When a is divided by b, the  [#permalink]

### Show Tags

16 Oct 2017, 04:06
nkmungila wrote:
a, b, c, d are positive integers. When a is divided by b, the remainder is 7. When c is divided by d, the remainder is 5. Which of
the following cannot be the value of the product b x d?

A. 48
B. 56
C. 63
D. 69
E. 140

Hi....
Remainders should tell us that b>7 and d>5...
So what can we say about the products..
1) minimum value 8*6=48
2) atleast two factors above 5, one out of which above 7..

Let's see the choices
A) 48-6*8... Ok
B) 56 - 7*8...ok
C) 63 - 7*9... Ok
D) 69 - 3*23... No other possibilities.. Answer
E) 140 - 7*20... Ok

D
_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

GMAT online Tutor

Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 3186
Location: United States (CA)
Re: a, b, c, d are positive integers. When a is divided by b, the  [#permalink]

### Show Tags

17 Oct 2017, 11:48
nkmungila wrote:
a, b, c, d are positive integers. When a is divided by b, the remainder is 7. When c is divided by d, the remainder is 5. Which of
the following cannot be the value of the product b x d?

A. 48
B. 56
C. 63
D. 69
E. 140

Recall that the remainder must be less than the divisor; thus, b must be greater than 7 since “when a is divided by b, the remainder is 7.” Similarly, d must be greater than 5 since “when c is divided by d, the remainder is 5.” Since b and d are positive integers, b ≥ 8 and d ≥ 6.

Next we can factor each answer choice. If the number can be factored into two numbers such that one of them is at least 8 and the other is at least 6, then it can be a value of b x d. However, if the number can’t be factored in the way described above, then it CANNOT be a value of b x d and that is the number we are looking for.

A. 48 = 8 x 6 (Yes)
B. 56 = 8 x 7 (Yes)
C. 63 = 9 x 7 (Yes)
D. 69 = 1 x 69 = 3 x 23 (No)
E. 140 = 20 x 7 (Yes)

Since 69 can only be factored as 1 x 69 or 2 x 23, we don’t have one factor ≥ 8 and the other ≥ 6, so 69 can’t be a value of b x d.

_________________

Scott Woodbury-Stewart
Founder and CEO

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

Re: a, b, c, d are positive integers. When a is divided by b, the &nbs [#permalink] 17 Oct 2017, 11:48
Display posts from previous: Sort by

# a, b, c, d are positive integers. When a is divided by b, the

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

# Events & Promotions

 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®.