Last visit was: 25 Nov 2024, 04:08 It is currently 25 Nov 2024, 04:08

Close

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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Own Kudos [?]: 3224 [6]
Given Kudos: 172
Location: India
WE:Education (Education)
Send PM
Most Helpful Community Reply
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Own Kudos [?]: 3224 [1]
Given Kudos: 172
Location: India
WE:Education (Education)
Send PM
General Discussion
Manager
Manager
Joined: 04 Jan 2019
Posts: 62
Own Kudos [?]: 114 [0]
Given Kudos: 5
Send PM
Intern
Intern
Joined: 11 Mar 2020
Posts: 11
Own Kudos [?]: 8 [3]
Given Kudos: 25
Send PM
Re: Four terms in Arithmetic progression have a sum of 28. [#permalink]
3
Seems difficult at first, but requires good concept knowledge :

a+a+x+a+2x+a+3x = 28
4a+6x = 28
2a+3x = 14

Possibility is out of a,b,c,d two can be negative or all 4 can be positive, so lets test for positive first :
2a+3x = 14
2(2)+3(4) = 14 , a=2 b=6 c=10 d=14 , this doesn't satisfy 5/6 eq.
2(4)+3(2) = 14 , a=4 b=6 c=8 d=10 , this satisfy 5/6 eq.

So d=10

Hope this correct
Manager
Manager
Joined: 18 Jan 2021
Posts: 81
Own Kudos [?]: 20 [0]
Given Kudos: 103
Send PM
Re: Four terms in Arithmetic progression have a sum of 28. [#permalink]
KarunMendiratta wrote:
Explanation:

Let the terms be (x - 3), (x - 1), (x + 1), and (x + 3)
So, (x - 3) + (x- 1) + (x + 1) + (x + 3) = 28
x = 7

Therfore, terms are 4, 6, 8, and 10

Let us check if x = 7 satisfies the second scenario;
\(\frac{(4)(10)}{(6)(8)} = \frac{40}{48} = \frac{5}{6}\)
We have a match

Col. A: 10
Col. B: 11

Hence, option B


How did you arrived at the decision of being the terms equal to (x - 3), (x - 1), (x + 1), and (x + 3)?
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Own Kudos [?]: 3224 [2]
Given Kudos: 172
Location: India
WE:Education (Education)
Send PM
Re: Four terms in Arithmetic progression have a sum of 28. [#permalink]
1
1
koala wrote:
KarunMendiratta wrote:
Explanation:

Let the terms be (x - 3), (x - 1), (x + 1), and (x + 3)
So, (x - 3) + (x- 1) + (x + 1) + (x + 3) = 28
x = 7

Therfore, terms are 4, 6, 8, and 10

Let us check if x = 7 satisfies the second scenario;
\(\frac{(4)(10)}{(6)(8)} = \frac{40}{48} = \frac{5}{6}\)
We have a match

Col. A: 10
Col. B: 11

Hence, option B


How did you arrived at the decision of being the terms equal to (x - 3), (x - 1), (x + 1), and (x + 3)?


While solving the Qs from AP and/or GP, assume the consecutive numbers as ... (a - 3d), (a - 2d), (a- d), a, (a + d), (a + 2d), (a + 3d), ....
This will help you save a lot of time.
User avatar
GRE Prep Club Legend
GRE Prep Club Legend
Joined: 07 Jan 2021
Posts: 5053
Own Kudos [?]: 75 [0]
Given Kudos: 0
Send PM
Re: Four terms in Arithmetic progression have a sum of 28. [#permalink]
Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Prep Club for GRE Bot
Re: Four terms in Arithmetic progression have a sum of 28. [#permalink]
Moderators:
GRE Instructor
84 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne