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.
Sep 28Live Online Class with Top GRE Expert Mike Butville
08:00 PM EDT
-10:00 PM EDT
Top scores are possible when you enroll in a powerful GRE course, taught live online + 6 months access to TTP GRE OnDemand video courses included! Class starts Mon/Wed Sept. 28, 2026 - Dec. 9, 2026, 8:00pm-10:00pm EST
In a certain sequence, the first term is -4, and every term
[#permalink]
16 Mar 2019, 10:26
16 Mar 2019, 10:26
Expert Reply
00:00
Question Stats:
66% (01:26) correct
33% (01:06) wrong based on 9 sessions
Hide Show timer Statistics
In a certain sequence, the first term is -4, and every term thereafter is defined by \(2 * |x| * \frac{1}{2}\), where x = preceding term. What is the sum of the first 300 terms?
A. It cannot be determined from the information given.
B. 0
C. 1186
D. 1192
E. 1200
A. It cannot be determined from the information given.
B. 0
C. 1186
D. 1192
E. 1200
Re: In a certain sequence, the first term is -4, and every term
[#permalink]
20 Mar 2019, 14:40
20 Mar 2019, 14:40
Expert Reply
First of all, we can multiply in any order. So:
\(2* |x| * \frac{1}{2} = |x| * 2 * \frac{1}{2} = |x| * 1 = |x|\)
So each term is just the absolute value of the term before it.
The first term is -4. Terms 2 to 300 are 4. So 299 terms are equal to 4, for a sum of 299*4 = 1196. The first term is -4, so the total sum is 1196 - 4 = 1192.
\(2* |x| * \frac{1}{2} = |x| * 2 * \frac{1}{2} = |x| * 1 = |x|\)
So each term is just the absolute value of the term before it.
The first term is -4. Terms 2 to 300 are 4. So 299 terms are equal to 4, for a sum of 299*4 = 1196. The first term is -4, so the total sum is 1196 - 4 = 1192.
Retired Moderator
Joined: 02 Jan 2020
Status:GRE Quant Tutor
Posts: 1141
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)
Re: In a certain sequence, the first term is -4, and every term
[#permalink]
20 Oct 2022, 07:50
20 Oct 2022, 07:50
Given that the first term is -4, and every term thereafter is defined by \(2 * |x| * \frac{1}{2}\), where x = preceding term. And we need to find What is the sum of the first 300 terms
Term 1, \(T_1\) = -4
Each term after \(T_1\) is given by \(2 * |x| * \frac{1}{2}\) = |x|, where x is the preceding term
\(T_2\) = | \(T_1\) | = | -4| = 4
( Watch this video to learn about the Basics of Absolute Value )
\(T_3\) = | \(T_2\) | = |4| = 4
Now, each term after this will be equal to 4 only as |4| = 4
=> Sum of first 300 terms = -4 + 4 + ... + 4 (-4 followed by 299 4's) = 4 + 4 + ... + 4 (298 4's) = 298 * 4 = 1192
So, Answer will be D
Hope it helps!
Watch the following video to learn How to Sequence problems
Term 1, \(T_1\) = -4
Each term after \(T_1\) is given by \(2 * |x| * \frac{1}{2}\) = |x|, where x is the preceding term
\(T_2\) = | \(T_1\) | = | -4| = 4
( Watch this video to learn about the Basics of Absolute Value )
\(T_3\) = | \(T_2\) | = |4| = 4
Now, each term after this will be equal to 4 only as |4| = 4
=> Sum of first 300 terms = -4 + 4 + ... + 4 (-4 followed by 299 4's) = 4 + 4 + ... + 4 (298 4's) = 298 * 4 = 1192
So, Answer will be D
Hope it helps!
Watch the following video to learn How to Sequence problems
