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: 2508
Given Kudos: 1053
GPA: 3.39
In a certain sequence, the term A_n is given by the formula A_n= {16-
[#permalink]
11 Jul 2021, 23:27
11 Jul 2021, 23:27
Expert Reply
00:00
Question Stats:
57% (04:35) correct
42% (03:16) wrong based on 7 sessions
Hide Show timer Statistics
In a certain sequence, the term \(A_n\) is given by the formula \(A_n= 16-\frac{(4- n)^3}{|n-4|}\) for all positive integers n ≠ 4, while \(A_4 = 16\). For which integer value of k greater than 2 is the mean of all values in the sequence from \(A_1\) through \(A_k\) equal to the median of those values?
(A) 6
(B) 7
(C) 8
(D) 9
(E) 10
(A) 6
(B) 7
(C) 8
(D) 9
(E) 10
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Given Kudos: 172
Location: India
WE:Education (Education)
In a certain sequence, the term A_n is given by the formula A_n= {16-
[#permalink]
13 Jul 2021, 22:19
13 Jul 2021, 22:19
2
1
Bookmarks
GeminiHeat wrote:
In a certain sequence, the term \(A_n\) is given by the formula \(A_n= 16-\frac{(4- n)^3}{|n-4|}\) for all positive integers n ≠ 4, while \(A_4 = 16\). For which integer value of k greater than 2 is the mean of all values in the sequence from \(A_1\) through \(A_k\) equal to the median of those values?
(A) 6
(B) 7
(C) 8
(D) 9
(E) 10
(A) 6
(B) 7
(C) 8
(D) 9
(E) 10
\(A_n= 16-\frac{(4-n)^3}{|n-4|}\)
\(A_1 = 7\)
\(A_2 = 12\)
\(A_3 = 15\)
\(A_4 = 16\)
\(A_5 = 17\)
\(A_6 = 20\)
\(A_7 = 25\)
\(A_8 = 32\)
\(A_9 = 41\)
I. \(k = 6\)
\(\frac{7+12+15+16+17+20}{6} = \frac{15+16}{2}\)
\(14.5 ≠ 15.5\)
II. \(k = 7\)
\(\frac{7+12+15+16+17+20+25}{7} = 16\)
\(16 = 16\)
Hence, option B
gmatclubot
In a certain sequence, the term A_n is given by the formula A_n= {16- [#permalink]
13 Jul 2021, 22:19
Moderators:
