Last visit was: 03 Jan 2025, 08:47 It is currently 03 Jan 2025, 08:47
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

Close

GRE Prep 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 GRE 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
PREVIOUS TOPIC
NEXT TOPIC

If k is a positive integer, and if the units’ digit

Tags :
Find Similar Topics  About  Add a Tag

Show Tags
Hide Tags

User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 30581
Own Kudos [?]: 36934 [1]
Given Kudos: 26116
Send PM
If k is a positive integer, and if the units’ digit [#permalink] New post   02 Aug 2021, 14:07
1
Expert Reply
00:00

Question Stats:

89% (00:58) correct 10% (03:09) wrong based on 28 sessions

Hide Show timer Statistics

If \(k\) is a positive integer, and if the units’ digit of \(k^2\) is 1 and the units' digit of \((k+1)^2\) is 0, what is the units' digit of \((k+2)^2\)?


(A) 1
(B) 3
(C) 5
(D) 7
(E) 9
ShowHide Answer
Official Answer
A
User avatar
G
motion2020
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Own Kudos [?]: 377 [2]
Given Kudos: 64
GRE 1: Q160 V152
Send PM
If k is a positive integer, and if the units’ digit [#permalink] New post   02 Aug 2021, 16:06
2
Of all integers only those ending with 1 and 9 result in squred integer's unit=1.
Given 1 and 9 or N1 and N9 are added by 1, the squared digits will ending in 0 for 9 or N9.
When added by 2, the unit's digit of N9 will be 1 for the squared integer results in unit's digit of 1 too. Answer is A
Carcass wrote:
If \(k\) is a positive integer, and if the units’ digit of \(k^2\) is 1 and the units' digit of \((k+1)^2\) is 0, what is the units' digit of \((k+2)^2\)?


(A) 1
(B) 3
(C) 5
(D) 7
(E) 9
Prep Club for GRE Bot
gmatclubot
If k is a positive integer, and if the units’ digit [#permalink]
02 Aug 2021, 16:06
Moderators:
adewale223
GRE Instructor
88 posts
bronaugust
GRE Forum Moderator
37 posts
BrushMyQuant
Moderator
1126 posts
VibhuAnurag
GRE Instructor
234 posts

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

Main navigation

Partners

GRE Resources

www.ets.org/gre | About | Terms and Conditions and Privacy Policy | Prep Club for GRE Rules | Contact