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.
A sequence a1 , a2 ,…is defined such that each term is
[#permalink]
19 Jul 2019, 09:00
19 Jul 2019, 09:00
1
Expert Reply
6
Bookmarks
00:00
Question Stats:
59% (01:05) correct
40% (01:02) wrong based on 110 sessions
Hide Show timer Statistics
A sequence \(a_1\), \(a_2\) ,…is defined such that each term is 3 less than the preceding term. Which of the following equations is consistent with this definition?
(A) \(a_{n+1} – 3 = a_n\)
(B) \(a_{n+1} + 3 = a_n\)
(C) \(3 – a_n = a_{n+1}\)
(D) \(3 – a_{n+1} = a_n\)
(E) \(a_n + 3 = a_{n+1}\)
(A) \(a_{n+1} – 3 = a_n\)
(B) \(a_{n+1} + 3 = a_n\)
(C) \(3 – a_n = a_{n+1}\)
(D) \(3 – a_{n+1} = a_n\)
(E) \(a_n + 3 = a_{n+1}\)
GRE Instructor
Joined: 19 Jan 2020
Status:Entrepreneur | GMAT, GRE, CAT, SAT, ACT coach & mentor | Founder @CUBIX | Edu-consulting | Content creator
Posts: 117
Given Kudos: 0
GPA: 3.72
Re: A sequence a1 , a2 ,…is defined such that each term is
[#permalink]
12 May 2020, 23:15
12 May 2020, 23:15
1
Carcass wrote:
A sequence \(a_1\), \(a_2\) ,…is defined such that each term is 3 less than the preceding term. Which of the following equations is consistent with this definition?
(A) \(a_{n+1} – 3 = a_n\)
(B) \(a_{n+1} + 3 = a_n\)
(C) \(3 – a_n = a_{n+1}\)
(D) \(3 – a_{n+1} = a_n\)
(E) \(a_n + 3 = a_{n+1}\)
(A) \(a_{n+1} – 3 = a_n\)
(B) \(a_{n+1} + 3 = a_n\)
(C) \(3 – a_n = a_{n+1}\)
(D) \(3 – a_{n+1} = a_n\)
(E) \(a_n + 3 = a_{n+1}\)
Each term is 3 less than the preceding term; thus:
a2 = a1 - 3
a3 = a2 - 3
a4 = a3 - 3 and so on
Thus, we have: a2 = a1 - 3, a3 = a1 - 6; a4 = a1 - 9 and so on
Thus: \(=> a_{n+1} = a_n - 3\)
Note:
=> a2 = a1 - 3 x 1, a3 = a1 - 3 x 2; a4 = a1 - 3 x 3 and so on
=> a2 = a1 - 3 x (2 - 1), a3 = a1 - 3 x (3 - 1); a4 = a1 - 3 x (4 - 1) and so on
Answer B
Re: A sequence a1 , a2 ,…is defined such that each term is
[#permalink]
31 May 2021, 02:23
31 May 2021, 02:23
1
a1,a2,a3,a4,........
where a2=a1-3
a3=a2-6
lets check the options we have n and n+1 in it so it means
a_(n+1)=a_n -3
a_n=a_(n+1)+3
option B is the answer.
where a2=a1-3
a3=a2-6
lets check the options we have n and n+1 in it so it means
a_(n+1)=a_n -3
a_n=a_(n+1)+3
option B is the answer.
