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In the sequence a1, a2, a3, , an,an=an1+an2. If a1=1 and a2=1
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03 May 2022, 01:00
03 May 2022, 01:00
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80% (00:57) correct
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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
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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
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Posts: 6218
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Re: In the sequence a1, a2, a3, , an,an=an1+an2. If a1=1 and a2=1
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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
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In the sequence a1, a2, a3, , an,an=an1+an2. If a1=1 and a2=1
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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
