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.
In the sequence a1, a2, a3, , an,an=an1+an2. If a1=1 and a2=1
[#permalink]
03 May 2022, 01:00
03 May 2022, 01:00
1
Expert Reply
1
Bookmarks
00:00
Question Stats:
80% (00:57) correct
19% (01:28) wrong based on 21 sessions
Hide Show timer Statistics
In the sequence \(a_1\), \(a_2\), \(a_3\), …, \(a_n\), \(a_n=a_{n−1}+a_{n−2}\). If \(a_1=1\) and \(a_2=1\), which of the following correctly expresses the first 5 terms of the sequence?
A. 1, 1, 2, 3, 4
B. 1, 1, 2, 3, 5
C. 1, 1, 2, 3, 6
D. 1, 1, 2, 4, 8
E. 1, 2, 3, 4, 5
A. 1, 1, 2, 3, 4
B. 1, 1, 2, 3, 5
C. 1, 1, 2, 3, 6
D. 1, 1, 2, 4, 8
E. 1, 2, 3, 4, 5
Part of the project: GRE Quantitative Comparison & Problem Solving Challenge
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
Retired Moderator
Joined: 10 Apr 2015
Posts: 6218
Given Kudos: 136
Re: In the sequence a1, a2, a3, , an,an=an1+an2. If a1=1 and a2=1
[#permalink]
03 May 2022, 05:24
03 May 2022, 05:24
1
Carcass wrote:
In the sequence \(a_1\), \(a_2\), \(a_3\), …, \(a_n\), \(a_n=a_{n−1}+a_{n−2}\). If \(a_1=1\) and \(a_2=1\), which of the following correctly expresses the first 5 terms of the sequence?
A. 1, 1, 2, 3, 4
B. 1, 1, 2, 3, 5
C. 1, 1, 2, 3, 6
D. 1, 1, 2, 4, 8
E. 1, 2, 3, 4, 5
A. 1, 1, 2, 3, 4
B. 1, 1, 2, 3, 5
C. 1, 1, 2, 3, 6
D. 1, 1, 2, 4, 8
E. 1, 2, 3, 4, 5
Given: \(a_n=a_{n−1}+a_{n−2}\)
So, \(a_3=a_{3−1}+a_{3−2}=a_{2}+a_{1} = 1 + 1 = 2\)
Similarly, \(a_4=a_{3}+a_{2} = 2 + 1 = 3\)
And, \(a_5=a_{4}+a_{3} = 3 + 2 = 5\)
So, the first five terms are: \(1, 1, 2, 3, 5\)
Answer: B
Moderator
Joined: 02 Jan 2020
Status:GRE Quant Tutor
Posts: 1126
Given Kudos: 9
Location: India
Concentration: General Management
Schools: XLRI Jamshedpur, India - Class of 2014
GMAT 1: 700 Q51 V31
GPA: 2.8
WE:Engineering (Computer Software)
In the sequence a1, a2, a3, , an,an=an1+an2. If a1=1 and a2=1
[#permalink]
25 Oct 2022, 10:47
25 Oct 2022, 10:47
Given that \(a_1=1\) and \(a_2=1\) and \(a_n=a_{n−1}+a_{n−2}\) and we need to find the first 5 terms of the sequence
\(a_1=1\) and \(a_2=1\) and \(a_n=a_{n−1}+a_{n−2}\)
=> \(a_3 = a_2 + a_1\) = 1 + 1 = 2
=> \(a_4 = a_3 + a_2\) = 2 + 1 = 3
=> \(a_5 = a_4 + a_3\) = 3 + 2 = 5
=> Series is 1, 1, 2, 3, 5
So, Answer will be B
Hope it helps!
Watch the following video to learn How to Sequence problems
\(a_1=1\) and \(a_2=1\) and \(a_n=a_{n−1}+a_{n−2}\)
=> \(a_3 = a_2 + a_1\) = 1 + 1 = 2
=> \(a_4 = a_3 + a_2\) = 2 + 1 = 3
=> \(a_5 = a_4 + a_3\) = 3 + 2 = 5
=> Series is 1, 1, 2, 3, 5
So, Answer will be B
Hope it helps!
Watch the following video to learn How to Sequence problems
