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.
GRE Prep Club Team Member
Joined: 20 Feb 2017
Posts: 2506
Given Kudos: 1055
GPA: 3.39
If S(n) is the sum of sequence 1, 2, 3, 4, ...n, in terms of n and S(n
[#permalink]
19 Apr 2022, 09:04
19 Apr 2022, 09:04
Expert Reply
4
Bookmarks
00:00
Question Stats:
66% (02:41) correct
33% (01:33) wrong based on 9 sessions
Hide Show timer Statistics
If S(n) is the sum of sequence 1, 2, 3, 4, ...n, in terms of n and S(n), S(2n)=?
(A) 2*S(n)
(B) n*S(n)
(C) 2n*S(n)
(D) 2S(n)+n^2
(E) S(n)+2n^2
(A) 2*S(n)
(B) n*S(n)
(C) 2n*S(n)
(D) 2S(n)+n^2
(E) S(n)+2n^2
Re: If S(n) is the sum of sequence 1, 2, 3, 4, ...n, in terms of n and S(n
[#permalink]
19 Apr 2022, 18:39
19 Apr 2022, 18:39
1
Quote:
If S(n) is the sum of sequence 1, 2, 3, 4, ...n, in terms of n and S(n), S(2n)=?
Using values, when n = 2
S(n) = S(2) = 1 + 2 = 3
S(2n) = S(4) = 1 + 2+ 3 + 4 = 10
substituting n =2 in the options, such that answer is 10
(A) 2*S(n) = 2 * S(2) = 2*3 = 6 wrong
(B) n*S(n) = 2 * S(2) = 6 wrong
(C) 2n*S(n) = 2*2*S(2) = 2*2*3 = 12 wrong
(D) 2S(n)+n^2 = 2*S(2) + 2^2 = 2*3 + 4 = 10 Correct
(E) S(n)+2n^2 = S(2) + 2*2^2 = 3 + 8 = 11 wrong
IMO D
gmatclubot
Re: If S(n) is the sum of sequence 1, 2, 3, 4, ...n, in terms of n and S(n [#permalink]
19 Apr 2022, 18:39
Moderators:
