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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
If k is a positive integer, and if the units’ digit of k 2 is 9 and th
[#permalink]
15 Aug 2021, 14:05
15 Aug 2021, 14:05
Expert Reply
00:00
Question Stats:
95% (01:05) correct
4% (00:41) wrong based on 21 sessions
Hide Show timer Statistics
If k is a positive integer, and if the units’ digit of \(k^2\) is 9 and the units’ digit of \((k + 1)^2\) is 6, what is the units’ digit of \((k + 2)^2\) ?
(A) 1
(B) 3
(C) 5
(D) 7
(E) 9
(A) 1
(B) 3
(C) 5
(D) 7
(E) 9
Retired Moderator
Joined: 19 Nov 2020
Posts: 326
Given Kudos: 64
GRE 1: Q160 V152
Re: If k is a positive integer, and if the units’ digit of k 2 is 9 and th
[#permalink]
15 Aug 2021, 17:34
15 Aug 2021, 17:34
mentally try digits from 0 to 9 for the units’ digit of \(k^2\) to be 9, only 3 and 7 works
mentally try digits 3 and 7 for the units’ digit of \((k+1)^2\) to be 6, only 3 works
calculate what is the units’ digit of \((k + 2)^2\), when k=3
the units’ digit of \((3 + 2)^2\) is 5
Answer is C
mentally try digits 3 and 7 for the units’ digit of \((k+1)^2\) to be 6, only 3 works
calculate what is the units’ digit of \((k + 2)^2\), when k=3
the units’ digit of \((3 + 2)^2\) is 5
Answer is C
Carcass wrote:
If k is a positive integer, and if the units’ digit of \(k^2\) is 9 and the units’ digit of \((k + 1)^2\) is 6, what is the units’ digit of \((k + 2)^2\) ?
(A) 1
(B) 3
(C) 5
(D) 7
(E) 9
(A) 1
(B) 3
(C) 5
(D) 7
(E) 9
gmatclubot
Re: If k is a positive integer, and if the units’ digit of k 2 is 9 and th [#permalink]
15 Aug 2021, 17:34
Moderators:
