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

It is currently 20 Sep 2019, 15:55

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

What is the remainder when -100 is divided by -30?

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

Hide Tags

Find Similar Topics 
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7896
GMAT 1: 760 Q51 V42
GPA: 3.82
What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 12 Mar 2016, 06:30
4
25
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

37% (00:49) correct 63% (00:50) wrong based on 241 sessions

HideShow timer Statistics

What is the remainder when -100 is divided by -30?

A. -10
B. 0
C. 10
D. 15
E. 20


* A solution will be posted in two days.

Bunuel s note: Source cannot be from OG because remainder questions are limited to positive integers on the GMAT. Because of this one can ignore this question altogether and move on.


_________________
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 $79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Most Helpful Expert Reply
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7831
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 12 Mar 2016, 06:37
6
5
MathRevolution wrote:
What is the remainder when -100 is divided by -30?

A. -10
B. 0
C. 10
D. 15
E. 20


* A solution will be posted in two days.


Hi,

If we know this RULE, we can answer the answer easily..

RULE- REMAINDER is always positive....



here \(-100 = -30*3-10\)so remainder is -10, which is not VALID answer
\(-100= -30*4+20..\)
Now th eremainder is 20, a positive quantity
ans 20
E

_________________
Most Helpful Community Reply
BSchool Forum Moderator
avatar
P
Joined: 05 Jul 2017
Posts: 499
Location: India
GMAT 1: 700 Q49 V36
GPA: 4
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 05 Aug 2018, 10:48
Since you simplified the fractions, the remainder is also simplified.

To get the original remainder you need to multiply the current remainder (i.e. 1) with the number that you simplified with (i.e. -10)

Hence, now the remainder is -10

A remainder cannot be negative. subtract the negative remainder from the divisor to get the correct remainder
=30 - 10
=20

Hence answer is 20

P.S : - You can try the above with an example such as 60/25.
_________________
General Discussion
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7896
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 14 Mar 2016, 17:59
1
2
What is the remainder when -100 is divided by -30?

A. -10
B. 0
C. 10
D. 15
E. 20


-> N,q,q,r are integers. p=divisor q=quotient, and r=remainder from N=pq+r, in which 0≤r<|p| is derived. That is, the remainder has no negative numbers. Thus, -100=(-30)(4)+20 -> 0≤20<|-30|=30. E is the answer.
_________________
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 $79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Current Student
User avatar
D
Joined: 12 Aug 2015
Posts: 2594
Schools: Boston U '20 (M)
GRE 1: Q169 V154
GMAT ToolKit User
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 17 Mar 2016, 00:32
chetan2u wrote:
MathRevolution wrote:
What is the remainder when -100 is divided by -30?

A. -10
B. 0
C. 10
D. 15
E. 20


* A solution will be posted in two days.


Hi,

If we know this RULE, we can answer the answer easily..

RULE- REMAINDER is always positive....



here \(-100 = -30*3-10\)so remainder is -10, which is not VALID answer
\(-100= -30*4+20..\)
Now th eremainder is 20, a positive quantity
ans 20
E




hey chetan2u I too marked D but with a hesitation..
I remember in my class 6 my teacher telling me that Remainder is always less than or equal to zero and divisor must be greater than than the remainder
here remainder is positive => YES
but it isn't < the divisor..
AM i missing something?

regards
_________________
Manager
Manager
User avatar
P
Joined: 13 Aug 2015
Posts: 205
GMAT 1: 710 Q49 V38
GPA: 3.82
WE: Corporate Finance (Retail Banking)
GMAT ToolKit User Reviews Badge
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 28 Apr 2017, 16:40
1
What is the remainder when -100 is divided by -30?
A. -10
B. 0
C. 10
D. 15
E. 20
_________________
If you like my posts, please give kudos. Help me unlock gmatclub tests.
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7831
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 28 Apr 2017, 19:21
mkrishnabdrr wrote:
What is the remainder when -100 is divided by -30?
A. -10
B. 0
C. 10
D. 15
E. 20



The main point here is that the remainder is always POSITIVE
So don't get trapped in -100=-30*3-10 and take -10 as remainder.
The remainder will be -100=-120+20=-30*4+20...
20..
E
_________________
Manager
Manager
User avatar
P
Joined: 13 Aug 2015
Posts: 205
GMAT 1: 710 Q49 V38
GPA: 3.82
WE: Corporate Finance (Retail Banking)
GMAT ToolKit User Reviews Badge
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 28 Apr 2017, 19:25
Why ×4? Why not ×5 or ×6?

Please give kudos, help me unlock Gmatclub tests. :)
_________________
If you like my posts, please give kudos. Help me unlock gmatclub tests.
Current Student
avatar
G
Joined: 18 Jan 2017
Posts: 82
Location: India
Concentration: Finance, Economics
GMAT 1: 700 Q50 V34
GMAT ToolKit User
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 28 Apr 2017, 19:48
When we are calculating remainders and we cancel out any signs/common terms it is imperative to add back the same to the final remainder to arrive at the final solution.
e.g remainder of 10/4 can be simplified to 5/2 (by cancelling out 2)---->5/2 gives us a remainder of 3
Hence the final remainder is 6 (3*2) <-----please note how 2 was multiplied back after arriving at the remainder by simplification

Applying the same concept in this problem, we can cancel the common term -1. In this case after removing the negative signs, Remainder of 100 divided by 30 is 10 and a negative remainder of -20 (Concept on Negative remainder discussed in the link/post below)

Now considering we had cancelled out the negative signs we need to multiply the same back. Thus the final remainders are -10 and 20.

Considering by definition remainders are positive (0<=r<d, where r=remainder and d=divisor), hence the solution is 20.

Please refer the below discussion for negative remainders
https://www.veritasprep.com/blog/2014/0 ... -the-gmat/


Kudos please if the post helped !
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58142
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 29 Apr 2017, 03:23
1
Manager
Manager
avatar
S
Joined: 26 Mar 2016
Posts: 60
Location: India
Concentration: Strategy, General Management
GMAT 1: 720 Q50 V36
GRE 1: Q166 V147
GPA: 3.3
WE: Other (Consulting)
GMAT ToolKit User Reviews Badge
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 13 Aug 2017, 05:26
mkrishnabdrr wrote:
Why ×4? Why not ×5 or ×6?

Please give kudos, help me unlock Gmatclub tests. :)



If we take x5, then remainder will be -50. But this is not valid because remainder cannot be greater than divisor
_________________
23 Kudos left to unlock next level. Help me by Contributing one for cause :) .. Please

My failed GMAT experience ... https://gmatclub.com/forum/gmat-bad-experience-640-need-suggestions-on-verbal-improvement-251308.html

My review on EmpowerGMAT : https://gmatclub.com/reviews/comments/empowergmat-online-course-345355767
Manager
Manager
avatar
B
Joined: 04 May 2014
Posts: 155
Location: India
WE: Sales (Mutual Funds and Brokerage)
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 19 Aug 2017, 23:56
Do we have some rule on taking modulus of divisor?

MathRevolution wrote:
What is the remainder when -100 is divided by -30?

A. -10
B. 0
C. 10
D. 15
E. 20


-> N,q,q,r are integers. p=divisor q=quotient, and r=remainder from N=pq+r, in which 0≤r<|p| is derived. That is, the remainder has no negative numbers. Thus, -100=(-30)(4)+20 -> 0≤20<|-30|=30. E is the answer.
Manager
Manager
avatar
B
Joined: 24 Jun 2017
Posts: 119
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 04 Sep 2017, 16:47
remainder is always positive
in such I case I prefer to use modular arithmetic , if it's not too complicated clock-based method is sufficient
One important thing to remember ff the dividend is positive we step clockwise, if it's negative we step counter-clockwise
100 is 3 time 30 and leaves us with 10, so start counting counter-clockwise from 29 ( after 3 full clock circles)
29 28 27 26 25 24 23 22 21 20
Senior Manager
Senior Manager
avatar
P
Joined: 17 Mar 2014
Posts: 431
GMAT ToolKit User Reviews Badge
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 05 Aug 2018, 08:19
1
When \(-100\) is divided by \(-30\), what is the remainder?

A. -20
B. -10
C. 0
D. 10
E. 20
Retired Moderator
User avatar
D
Joined: 30 Jan 2015
Posts: 801
Location: India
Concentration: Operations, Marketing
GPA: 3.5
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 05 Aug 2018, 08:49
ammuseeru wrote:
When \(-100\) is divided by \(-30\), what is the remainder?

Since the remainder is always positive, equation can not be -100 = (-30)*3 - 10
Therefore,
-100 = (-30)*4 + 20
Remainder = 20

Hence, E.
_________________
The few, the fearless !

Thanks :-)
IIMA, IIMC School Moderator
User avatar
V
Joined: 04 Sep 2016
Posts: 1371
Location: India
WE: Engineering (Other)
CAT Tests
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 05 Aug 2018, 09:11
1
ammuseeru MathRevolution KarishmaB Bunuel pushpitkc pikolo2510 chetan2u niks18


Quote:
When \(-100\) is divided by \(-30\), what is the remainder?


Why we can not write:

\(-100\) is divided by \(-30\)

as

\(100\) is divided by \(30\) and get remainder as 1 after simplifying fractions?
_________________
It's the journey that brings us happiness not the destination.

Feeling stressed, you are not alone!!
Retired Moderator
User avatar
V
Joined: 27 Oct 2017
Posts: 1242
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 05 Aug 2018, 18:30
Hiii
Whenever we cancel out common terms before dividing to find reminder, always remember to multiply that common factor to get the actual remainder.
Please see this.
Attachment:
IMG-20180806-WA0000_1533518866835.jpg
IMG-20180806-WA0000_1533518866835.jpg [ 73.05 KiB | Viewed 1893 times ]


adkikani wrote:
ammuseeru MathRevolution KarishmaB Bunuel pushpitkc pikolo2510 chetan2u niks18


Quote:
When \(-100\) is divided by \(-30\), what is the remainder?


Why we can not write:

\(-100\) is divided by \(-30\)

as

\(100\) is divided by \(30\) and get remainder as 1 after simplifying fractions?

_________________
VP
VP
User avatar
D
Joined: 09 Mar 2016
Posts: 1249
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 06 Aug 2018, 03:38
gmatbusters \(\frac{-100}{-30}\) isnt this fraction valid ? division of two negative numbers yields positive number, right ? IF SO, then

WHY \(\frac{-100}{-30}\)= \(3.10\) isnt it correct answer arithmetically-mathematically :lol: !?
Retired Moderator
User avatar
V
Joined: 27 Oct 2017
Posts: 1242
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 06 Aug 2018, 04:18
Please see my detailed explanation, how to find remainder when we cancel out the common terms.

dave13 wrote:
gmatbusters \(\frac{-100}{-30}\) isnt this fraction valid ? division of two negative numbers yields positive number, right ? IF SO, then

WHY \(\frac{-100}{-30}\)= \(3.10\) isnt it correct answer arithmetically-mathematically :lol: !?


Posted from my mobile device
_________________
VP
VP
User avatar
D
Joined: 09 Mar 2016
Posts: 1249
Re: What is the remainder when -100 is divided by -30?  [#permalink]

Show Tags

New post 06 Aug 2018, 04:24
gmatbusters wrote:
Please see my detailed explanation, how to find remainder when we cancel out the common terms.

dave13 wrote:
gmatbusters \(\frac{-100}{-30}\) isnt this fraction valid ? division of two negative numbers yields positive number, right ? IF SO, then

WHY \(\frac{-100}{-30}\)= \(3.10\) isnt it correct answer arithmetically-mathematically :lol: !?


Posted from my mobile device



gmatbusters your explanation is DETAILED. thank you for taking time to explain. But I cant see those DETAILS :lol: its impossible for me to decode your handwritten DETAILS :-)
GMAT Club Bot
Re: What is the remainder when -100 is divided by -30?   [#permalink] 06 Aug 2018, 04:24

Go to page    1   2    Next  [ 27 posts ] 

Display posts from previous: Sort by

What is the remainder when -100 is divided by -30?

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





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne