Last visit was: 14 Jul 2025, 02:46 It is currently 14 Jul 2025, 02:46
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
User avatar
Zarrolou
Joined: 02 Sep 2012
Last visit: 11 Dec 2013
Posts: 848
Own Kudos:
5,073
 [78]
Given Kudos: 219
Status:Far, far away!
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
Posts: 848
Kudos: 5,073
 [78]
7
Kudos
Add Kudos
71
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
VeritasPrepRon
User avatar
Veritas Prep GMAT Instructor
Joined: 11 Dec 2012
Last visit: 13 Jul 2025
Posts: 308
Own Kudos:
682
 [16]
Given Kudos: 66
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 308
Kudos: 682
 [16]
9
Kudos
Add Kudos
7
Bookmarks
Bookmark this Post
User avatar
nave
Joined: 08 Dec 2012
Last visit: 15 May 2016
Posts: 54
Own Kudos:
1,465
 [13]
Given Kudos: 31
Location: United Kingdom
WE:Engineering (Consulting)
Posts: 54
Kudos: 1,465
 [13]
8
Kudos
Add Kudos
4
Bookmarks
Bookmark this Post
General Discussion
User avatar
yezz
User avatar
Retired Moderator
Joined: 05 Jul 2006
Last visit: 26 Apr 2022
Posts: 837
Own Kudos:
1,644
 [3]
Given Kudos: 49
Posts: 837
Kudos: 1,644
 [3]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
x = 5k+2 , y = 5t+1

x+y = 5 (k+t) + 3 thus remainder when divided by 10 depends on (k+t) if k+t are non -ve even integer r = 3 , if +ve odd remainder is 8

from choices 8 is the right choice
avatar
ppskc1989
Joined: 23 Apr 2013
Last visit: 06 Sep 2023
Posts: 17
Own Kudos:
Given Kudos: 1
Posts: 17
Kudos: 74
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Zarrolou
When divided by 5, x has a remainder of 2 and y has a remainder of 1. Which of the following could be the remainder when x + y is divided by 10?

A)6
B)7
C)8
D)9
E)0

Given data can be represented as \(x = 5*p + 2\) and \(y = 5*q + 1\), where p and q are non negative integers.

Hence \(x+y = 5*k + 3\), k is some non negative integer.

Now observe that the possible remainders obtained when 5*k is divided by 10 are 0 and 5, depending on the parity of k. (0 when k is even, 5 when k is odd)

Hence it follows that the possible remainders when 5*k + 3 is divided by 10 are 3 and 8.
8 is in the given options.

Hence correct option is C :)
User avatar
karishmatandon
Joined: 14 Feb 2013
Last visit: 04 Jan 2014
Posts: 17
Own Kudos:
Given Kudos: 14
Schools: Duke '16
Schools: Duke '16
Posts: 17
Kudos: 239
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Can anybody explain how to use picking numbers strategy for such a problem?
avatar
ppskc1989
Joined: 23 Apr 2013
Last visit: 06 Sep 2023
Posts: 17
Own Kudos:
74
 [1]
Given Kudos: 1
Posts: 17
Kudos: 74
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
karishmatandon
Can anybody explain how to use picking numbers strategy for such a problem?

x is of the form 5*p +2 and y is of the form 5*q + 1

Look at the options. All of them are greater than 5.

So choose x and y such that their sum is greater than 5 and less than 10 (because that will simply represent the remainder we are looking for.)

For instance x = 7 and y = 1 can be taken.

Similarly x = 2 and y = 6 can be taken.

Hope this answers your question. :)
User avatar
karishmatandon
Joined: 14 Feb 2013
Last visit: 04 Jan 2014
Posts: 17
Own Kudos:
Given Kudos: 14
Schools: Duke '16
Schools: Duke '16
Posts: 17
Kudos: 239
Kudos
Add Kudos
Bookmarks
Bookmark this Post
ppskc1989
karishmatandon
Can anybody explain how to use picking numbers strategy for such a problem?

x is of the form 5*p +2 and y is of the form 5*q + 1

Look at the options. All of them are greater than 5.

So choose x and y such that their sum is greater than 5 and less than 10 (because that will simply represent the remainder we are looking for.)

For instance x = 7 and y = 1 can be taken.

Similarly x = 2 and y = 6 can be taken.

Hope this answers your question. :)

Oh..k..
i was just considering, 7,6 or 2,1
so i was only getting 3 as the remainder for x + y,
thanks for the explanation
avatar
Scorpserp
Joined: 20 Mar 2013
Last visit: 28 Dec 2013
Posts: 6
Own Kudos:
7
 [2]
Given Kudos: 5
GMAT Date: 07-25-2013
Posts: 6
Kudos: 7
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
karishmatandon
Can anybody explain how to use picking numbers strategy for such a problem?

hi

i used this method to solve so hope it helps u even

"x divided by 5 gives remainder 2"
=>any multiple of 5 will have units digit 0 or 5 so x would have units digit 2 or 7

and since we are to calculate for remainder when divided by 10 our main concern is the units digit only

"y divided by 5 gives remainder 1"
=> y would have units digit 1 or 6


for units digit of x+y we can take all combinations of x and y
(2,1) units digit 3
(2,6) units digit 8
(7,1) units digit 8
(7,6) units digit 3

so x+y will have units digit either 3 or 8
so x+y wen divided by 10 wud give either 8 or 3 as remainder
avatar
krrish
Joined: 04 Mar 2013
Last visit: 03 Feb 2014
Posts: 46
Own Kudos:
Given Kudos: 6
Location: India
Concentration: General Management, Marketing
GPA: 3.49
WE:Web Development (Computer Software)
Posts: 46
Kudos: 14
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Zarrolou
When divided by 5, x has a remainder of 2 and y has a remainder of 1. Which of the following could be the remainder when x + y is divided by 10?

A. 6
B. 7
C. 8
D. 9
E. 0


given x-2 is divisible by 5 and y-1 is also divisible by 5,
there could be either a even or odd multiple of 5, so

consider all possible varieties we get
if both are even or if both are odd
x+y makes it even
so remainder is 3 => 2+1

but if one is add and other is even then we get

5 +2+1 = 8,

hence solved.

please ping me if u need any further explanation .....
User avatar
gracie
Joined: 07 Dec 2014
Last visit: 11 Oct 2020
Posts: 1,035
Own Kudos:
Given Kudos: 27
Posts: 1,035
Kudos: 1,860
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Zarrolou
When divided by 5, x has a remainder of 2 and y has a remainder of 1. Which of the following could be the remainder when x + y is divided by 10?

A. 6
B. 7
C. 8
D. 9
E. 0

least possible value of x=2
least possible value of y=1
(2+1)/10 gives a remainder of 3--not listed
next least value of y=6
(2+6)/10 gives a remainder of 8
C
User avatar
ScottTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 14 Oct 2015
Last visit: 13 Jul 2025
Posts: 21,091
Own Kudos:
26,151
 [4]
Given Kudos: 296
Status:Founder & CEO
Affiliations: Target Test Prep
Location: United States (CA)
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 21,091
Kudos: 26,151
 [4]
3
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Zarrolou
When divided by 5, x has a remainder of 2 and y has a remainder of 1. Which of the following could be the remainder when x + y is divided by 10?

A. 6
B. 7
C. 8
D. 9
E. 0


We should recall that when dividing by 5, we only need to know the units digit of the divisor to determine the remainder. Thus, when x is divided by 5 and the remainder is 2, the units digit of x must be either 7 or 2. Also, when y is divided by 5 and the remainder is 1, the units digit of y must be either 6 or 1.

Likewise, when dividing by 10, we only need to know the units digit of the divisor to determine the remainder. Let’s now determine some possible sums of x and y.

x + y = 7 + 6 = 13, which has a remainder of 3 when divided by 10.

x + y = 7 + 1 = 8, which has a remainder of 8 when divided by 10.

x + y = 2 + 6 = 8, which has a remainder of 8 when divided by 10.

x + y = 2 + 1 = 3, which has a remainder of 3 when divided by 10.

Thus, the possible remainders when x + y is divided by 10 are 3 and 8. Since only 8 is given in the answer choices, the correct answer is C.

Answer: C
User avatar
gracie
Joined: 07 Dec 2014
Last visit: 11 Oct 2020
Posts: 1,035
Own Kudos:
1,860
 [1]
Given Kudos: 27
Posts: 1,035
Kudos: 1,860
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Zarrolou
When divided by 5, x has a remainder of 2 and y has a remainder of 1. Which of the following could be the remainder when x + y is divided by 10?

A. 6
B. 7
C. 8
D. 9
E. 0

five least values of x=2 7 12 17 22 27
five least values of y= 1 6 11 16 21
note that all x+y values sum to a 3 or 8 units digit
C
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 37,375
Own Kudos:
Posts: 37,375
Kudos: 1,010
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.
Moderators:
Math Expert
102569 posts
PS Forum Moderator
691 posts